S
Abbreviation with 9 meanings
| Stands for | South |
|---|---|
| Meanings | 9 |
| Categories | Geography & Places, Units & Measurements, Government & Politics, Science & Engineering, Texting & Internet Slang, Sports, Medical |
| Also written | /s, s, S., s̄ |
S has nine meanings. The most common are South (direction) and Second (time); it can also stand for Senate (bill prefix), Sulfur, Sarcasm (tone indicator), Safety and Sine (without), plus 2 more listed below.
Meanings of S at a glance
| # | S stands for | Context |
|---|---|---|
| 1 | South | Geography & Places › Direction |
| 2 | Second | Units & Measurements › Time |
| 3 | Senate (bill prefix) | Government & Politics › Political |
| 4 | Sulfur | Science & Engineering › Chemical Element |
| 5 | Sarcasm (tone indicator) | Texting & Internet Slang › Social Media |
| 6 | Safety | Sports › American Football |
| 7 | Sine (without) | Medical › Prescription |
| 8 | Saturday (schedule code) | Units & Measurements › Day of the Week |
| 9 | Siemens | Units & Measurements › Metric and SI Unit |
1. South
Geography & Places · Direction Abbreviations
Cardinal direction toward the South Pole, at 180 degrees. In street addresses S marks the part of a street south of the dividing baseline, as in 1200 S State St in Chicago, where Madison Street divides north from south.
Example: Turn onto S Lamar Blvd and the restaurant is on the left.
S also means second (time), sulfur and small in clothing sizes. Pilots and navigators give headings in degrees rather than letters, so 180 means due south.
2. Second (s)
Units & Measurements · Time Abbreviations
The SI base unit of time, defined since 1967 by the cesium-133 atom as exactly 9,192,631,770 periods of the radiation from a specific atomic transition. Scientific and technical writing uses s for durations, lap times and rates such as m/s.
Example: Usain Bolt's 100 m world record of 9.58 s was set in Berlin in 2009.
The symbol is s with no period and no plural (5 s, not 5 secs); everyday English prefers sec. Leap seconds were inserted into UTC 27 times between 1972 and 2016 to keep atomic time in step with Earth's rotation, and in 2022 the General Conference on Weights and Measures resolved to stop adding them by 2035. Arcseconds use the same word for a tiny angle.
3. Senate (bill prefix) (S.)
Government & Politics · Political Abbreviations
Senate counterpart of H.R., placed before the number of a bill introduced in the US Senate, as in "S. 2155". Senate bills are numbered in order of introduction and renumbered with each new Congress.
Example: S. 2155 eased some Dodd-Frank requirements for midsize banks when it became law in 2018.
A bill passed by the Senate goes to the House, which may pass it unchanged, amend it or set it aside. Revenue bills must originate in the House under the Constitution, so the Senate sometimes replaces the entire text of a House bill to use it as a "shell". The prefix is written "S." followed by a space and the number.
4. Sulfur
Science & Engineering · Chemical Element Abbreviations
Sulfur, atomic number 16, is a bright yellow nonmetal found near volcanoes and recovered in vast amounts from natural gas and oil refining. Most of it becomes sulfuric acid, the world's most produced industrial chemical, which in turn makes fertilizer. Sulfur also vulcanizes rubber and forms the disulfide bridges that shape proteins.
Example: Diesel sold in the United States must contain no more than 15 ppm S under the ultra-low sulfur standard.
Known since antiquity as brimstone ("burning stone"), sulfur was confirmed as an element by Lavoisier in 1777. The symbol comes from Latin sulpur, later spelled sulfur. IUPAC adopted the spelling sulfur in 1990, and it is now standard in science even in Britain, where sulphur persists in everyday writing. The rotten-egg smell blamed on sulfur actually comes from hydrogen sulfide.
5. Sarcasm (tone indicator) (/s)
Texting & Internet Slang · Social Media Abbreviations
Tone tag added to the end of a message to signal that it is sarcastic and should not be taken literally. Common on Reddit, Discord, X and Tumblr.
Example: Oh great, another Monday meeting at 8 a.m., my favorite thing /s
Descends from the mock-HTML "</sarcasm>" tag used on forums in the 1990s and 2000s. Some users see /s as unnecessary, others as helpful because sarcasm is hard to detect in text. Part of a broader system of tone indicators.
6. Safety
Sports · American Football Abbreviations
Deep defensive back who lines up furthest from the line of scrimmage, protecting against long passes and supporting run defense. Most defenses use two safeties, a free safety and a strong safety. Separately, a safety is also a two-point score when the offense is downed in its own end zone.
Example: The S read the quarterback's eyes and cut in front of the deep throw for an interception.
The position name reflects its role as the last line of defense. The scoring play called a safety is worth two points, and the scoring team also receives the ball on the free kick that follows. Rosters show the position as S, while scoring summaries spell out "Safety".
7. Sine (without) (s̄)
Medical · Prescription Abbreviations
Charting and prescription shorthand meaning "without", written as an s with a bar above it, as in "s̄ food" or "chest pain s̄ radiation". It pairs with c̄ (cum, with).
Example: CP s̄ diaphoresis or SOB; take tabs s̄ food.
Latin "sine", "without", familiar from "sine qua non". In medication directions the overbar can disappear in electronic copies, leaving an ambiguous "s", which is why plain English is preferred on labels and in orders.
8. Saturday (schedule code)
Units & Measurements · Day of the Week Abbreviations
A one-letter code for Saturday on calendars and timetables, though it is ambiguous because Sunday also starts with S. Calendar grids labeled S M T W T F S rely on position: the first S is Sunday and the last is Saturday.
Example: Lab open M to F 8 to 8, S 10 to 4; closed Su.
Registrar systems that need distinct codes often write S for Saturday and U or Su for Sunday. Pill organizers and US wall calendars that start on Sunday place S at both ends of the row. Elsewhere S can mean small, south or second, so a legend helps.
9. Siemens
Units & Measurements · Metric and SI Unit Abbreviations
Electrical conductance, the reciprocal of resistance: a conductor of 1 ohm has a conductance of 1 S. Water-quality meters report conductivity in microsiemens per centimeter to estimate dissolved salts.
Example: Conductivity at the outfall was 1,200 uS/cm, well above the upstream reading.
Named after German engineer and industrialist Werner von Siemens. The word is the same in singular and plural (1 siemens, 10 siemens). Older American texts used the mho, ohm spelled backward, for the same unit. Capital S must not be confused with lowercase s, the second.
Related abbreviations
More direction abbreviations
- NE – Northeast
- NNE – North-northeast
- NNW – North-northwest
- NW – Northwest
- SB – Southbound
- SE – Southeast
- SSE – South-southeast
- SSW – South-southwest
See all 23 direction abbreviations →
More time abbreviations
- Q4 – Fourth quarter
- QoQ – Quarter over quarter
- QTD – Quarter to date
- qtr – Quarter
- sec – Second
- T – Time designator (ISO 8601)
- wk – Week
- WoW – Week over week
See all 51 time abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.