Sr.
Abbreviation with 12 meanings
| Stands for | Senior (job level) |
|---|---|
| Meanings | 12 |
| Categories | Business & Finance, Science & Engineering, Military, Religion, Medical, Transportation & Travel, Units & Measurements, Sports, Arts & Entertainment, Geography & Places |
| Also written | SR, Sr, sr |
Sr. has 12 meanings. The most common are Senior (job level) (job title) and Special relativity (physics); it can also stand for Seaman Recruit, Sister, Sustained release, Systematic review and State Route, plus 5 more listed below.
Meanings of Sr. at a glance
| # | Sr. stands for | Context |
|---|---|---|
| 1 | Senior (job level) | Business & Finance › Job Title |
| 2 | Special relativity | Science & Engineering › Physics |
| 3 | Seaman Recruit | Military › US Navy and Coast Guard Rank |
| 4 | Sister | Religion › Religious Title |
| 5 | Sustained release | Medical › Pharmacy |
| 6 | Systematic review | Medical › Medical Research |
| 7 | State Route | Transportation & Travel › Driving |
| 8 | Steradian | Units & Measurements › Metric and SI Unit |
| 9 | Strontium | Science & Engineering › Chemical Element |
| 10 | Strike rate | Sports › Other Sports |
| 11 | Stage right | Arts & Entertainment › Film, Television and Theater |
| 12 | Suriname | Geography & Places › Country Code |
1. Senior (job level)
Business & Finance · Job Title Abbreviations · also used in general use
Marks a more experienced level of a role in job titles, as in "Sr. Software Engineer" or "Sr. Accountant." Senior titles usually require several years of experience and bring higher pay and broader responsibility.
Example: Job posting: Sr. Data Analyst, five or more years of SQL experience required.
Written with a period in American English (Sr.) and often without in British English (Sr or Snr). In personal names, Sr. distinguishes a father from a son with the same name, as in John Smith Sr., a separate usage. Career ladders often run junior, mid-level, senior, staff, principal.
2. Special relativity (SR)
Science & Engineering · Physics Abbreviations
Einstein's 1905 theory of space and time for observers moving at constant velocity, built on the principle that the speed of light is the same for everyone. It predicts time dilation, length contraction, the relativity of simultaneity and the equivalence of mass and energy, E = mc2.
Example: Muons created high in the atmosphere reach the ground only because SR time dilation stretches their short lifetimes.
Einstein published it in the paper "On the Electrodynamics of Moving Bodies," one of four landmark papers of his 1905 "miracle year." Particle accelerators and GPS must account for SR effects every day. General relativity extended the theory to include gravity and acceleration.
3. Seaman Recruit (SR)
Military · US Navy and Coast Guard Rank Abbreviations
Entry enlisted rank in the US Navy and Coast Guard, pay grade E-1, held by most recruits during boot camp. Navy recruits train at Recruit Training Command, Great Lakes, Illinois, and Coast Guard recruits at Training Center Cape May, New Jersey.
Example: SR Thompson passed his third-class swim qualification during week two at Recruit Training Command.
Recruits bound for engineering, aviation, construction or medical jobs may instead be designated Fireman Recruit (FR), Airman Recruit (AR), Constructionman Recruit (CR) or Hospitalman Recruit (HR). Navy E-1s normally advance to E-2 after nine months of service. Recruits with college credit, JROTC or Eagle Scout status can enlist at a higher grade.
4. Sister
Religion · Religious Title Abbreviations
Title for women religious, members of Catholic, Anglican, Lutheran and Orthodox communities who take vows, especially those in active ministry such as teaching, nursing and social work. It precedes the name, as in "Sr. Helen Prejean, CSJ".
Example: Sr. Mary Scullion has worked with Philadelphia's homeless for decades.
Strictly, "nun" refers to cloistered women in contemplative orders, while "sister" refers to women in apostolic communities, though everyday usage treats the words as interchangeable. Context distinguishes Sr. (Sister) from Sr. (Senior) after a man's name. In Spanish-speaking countries the equivalent title is Sor or Hermana.
5. Sustained release (SR)
Medical · Pharmacy Abbreviations
Suffix for formulations that release drug gradually, as in Wellbutrin SR, Calan SR and diclofenac SR. SR products are often taken twice daily, between immediate-release and once-daily extended-release versions.
Example: Bupropion SR 150 mg BID, at least 8 hours apart to lower seizure risk.
Bupropion illustrates why suffixes matter: the IR form is dosed three times daily, SR twice daily and XL once daily, and the maximum doses differ. Prescriptions that omit the suffix are a common source of pharmacy callbacks. In British usage "SR" (slow release) appears on some older products.
6. Systematic review (SR)
Medical · Medical Research Abbreviations
Review that answers a focused question by searching for all relevant studies with a predefined, reproducible method, assessing their quality and synthesizing the results, sometimes with a meta-analysis. Well-conducted systematic reviews sit near the top of most evidence hierarchies.
Example: SR of 14 RCTs found no reduction in mortality with the supplement.
Protocols are often registered in advance in PROSPERO to reduce selective reporting. The Cochrane Collaboration, founded in 1993, produces many of the best-known reviews. Narrative reviews, by contrast, summarize literature without a systematic search and are more prone to bias.
7. State Route (SR)
Transportation & Travel · Driving Abbreviations · also used in geography
Designation for a state highway in many US states, such as SR 1 along the California coast or SR 520 in Seattle. Some states use other labels, such as State Highway or a state's initials.
Example: Take SR 89 north from Tahoe City to reach Truckee.
Each state numbers and signs its own routes, so "SR 1" in California and "SR 1" in another state are unrelated roads. Shield shapes differ by state, such as California's spade-shaped sign. Washington, Arizona and Florida commonly write "SR."
8. Steradian (sr)
Units & Measurements · Metric and SI Unit Abbreviations
The SI unit of solid angle, the three-dimensional counterpart of the radian. A full sphere subtends 4π steradians, about 12.57 sr, at its center; the unit appears in definitions of luminous intensity and radiance.
Example: The lamp emits 800 lumens over roughly 2π sr, the hemisphere in front of it.
One candela equals one lumen per steradian, which is how the steradian links a light source's intensity to its total output. Radiometry uses watts per steradian for radiant intensity. The name combines Greek stereos, solid, with radian. Lowercase sr distinguishes it from Sr, the chemical symbol for strontium.
9. Strontium (Sr)
Science & Engineering · Chemical Element Abbreviations
Strontium, element 38, produces the crimson red of fireworks and road flares. A soft alkaline earth metal, it behaves chemically like calcium, so radioactive strontium-90 from nuclear fallout lodges in bones; stable strontium compounds were once used in the glass of television tubes.
Example: Red star shells rely on Sr nitrate, while green effects use barium compounds.
Adair Crawford and William Cruickshank recognized a new earth in 1790 in a mineral from lead mines near Strontian, a village in the Scottish Highlands that gave the element its name. Humphry Davy isolated the metal in 1808. Strontium-90, with a half-life of about 29 years, was monitored in children's baby teeth during the era of atmospheric nuclear testing.
10. Strike rate (SR)
Sports · Other Sports Abbreviations
Cricket statistic with two meanings: for batters, runs scored per 100 balls faced; for bowlers, balls bowled per wicket taken. A batting SR above 150 is excellent in T20 cricket.
Example: He scored 64 off 32 balls at an SR of 200.
Batting strike rate matters most in limited-overs formats, while Test cricket values staying in. For bowlers, lower strike rates are better. In other fields SR can mean senior or a sound recording.
11. Stage right (SR)
Arts & Entertainment · Film, Television and Theater Abbreviations
Right side of the stage from the performer's point of view facing the audience, the audience's left. Blocking notes and prompt books abbreviate it SR.
Example: Props table is SR, next to the fly rail.
Directions combine to describe areas, such as DSR (downstage right) and USR (upstage right). Fly systems and stage manager desks often sit on one side, giving theaters their own traditions. In cricket SR means strike rate.
12. Suriname (SR)
Geography & Places · Country Code Abbreviations
Smallest country in South America and the only one with Dutch as its official language, with Paramaribo as its capital and SUR as its alpha-3 code. Rainforest covers about 93 percent of its land.
Example: Flights from Amsterdam to Paramaribo, SR run several times a week.
The language code sr is Serbian. Suriname became independent from the Netherlands in 1975. SR also abbreviates senior, as in Sr.
Related abbreviations
More job title abbreviations
- SA – Solutions architect
- SDE – Software development engineer
- SDR – Sales development representative
- SE – Sales engineer
- SRE – Site reliability engineer
- SVP – Senior vice president
- SWE – Software engineer
- TL – Team lead
See all 70 job title abbreviations →
More physics abbreviations
- SLAC – SLAC National Accelerator Laboratory
- SM – Standard Model
- sonar – Sound navigation and ranging
- SQUID – Superconducting quantum interference device
- STM – Scanning tunneling microscope
- SUSY – Supersymmetry
- TEM – Transmission electron microscope
- TOE – Theory of everything
See all 68 physics abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.