F
Abbreviation with 9 meanings
| Stands for | Degree Fahrenheit |
|---|---|
| Meanings | 9 |
| Categories | Units & Measurements, Science & Engineering, Law & Legal, Arts & Entertainment, Writing & Everyday |
| Also written | f, F., f. |
F has nine meanings. The most common are Degree Fahrenheit (engineering unit) and F-statistic (statistics); it can also stand for Farad, Friday (schedule code), Fluorine, Federal Reporter and Forte, plus 2 more listed below.
Meanings of F at a glance
| # | F stands for | Context |
|---|---|---|
| 1 | Degree Fahrenheit | Units & Measurements › Engineering Unit |
| 2 | F-statistic | Units & Measurements › Statistics |
| 3 | Farad | Units & Measurements › Metric and SI Unit |
| 4 | Friday (schedule code) | Units & Measurements › Day of the Week |
| 5 | Fluorine | Science & Engineering › Chemical Element |
| 6 | Federal Reporter | Law & Legal › Legal Citation |
| 7 | Forte | Arts & Entertainment › Music |
| 8 | Femto- (quadrillionth) | Units & Measurements › Metric and SI Unit |
| 9 | And the following (page) | Writing & Everyday › Citation and Bibliography |
1. Degree Fahrenheit
Units & Measurements · Engineering Unit Abbreviations
The temperature scale used in the United States for weather, cooking and body temperature, on which water freezes at 32°F and boils at 212°F at sea level. Normal body temperature is about 98.6°F.
Example: Preheat the oven to 350 F and bake for 25 minutes.
Devised in 1724 by Daniel Gabriel Fahrenheit, a physicist born in Danzig who worked in the Dutch Republic. To convert to Celsius, subtract 32 and multiply by 5/9; −40 is the same on both scales. Besides the US, only a few places such as the Bahamas, Belize, the Cayman Islands, Palau and Liberia mainly use it. Formal text writes °F; plain F is common in recipes.
2. F-statistic
Units & Measurements · Statistics Abbreviations
The test statistic in ANOVA and regression, a ratio of two variances: the variance explained by the model or groups divided by the unexplained variance. Large F values suggest real differences between group means.
Example: Group means differed significantly, F(2, 87) = 6.34, p = .003.
The F distribution is named for Ronald Fisher, whose analysis of variance it underpins; George Snedecor tabulated it and chose the letter in Fisher's honor in the 1930s. Results report two degrees-of-freedom values, for the numerator and denominator, in parentheses. The test uses the upper tail only.
3. Farad
Units & Measurements · Metric and SI Unit Abbreviations
Capacitance at which one coulomb of charge raises a capacitor's voltage by one volt. The farad is a very large unit, so real components are rated in microfarads, nanofarads and picofarads, while supercapacitors reach hundreds or thousands of farads.
Example: The supercapacitor bank uses 3,000 F cells rated at 2.7 volts each.
Honors English scientist Michael Faraday. Capacitor markings use several forms of microfarad: μF, uF, MF, MFD and mfd all mean 10^-6 F on older parts and HVAC run capacitors, an exception to the rule that capital M means mega-. A capital F also stands for degrees Fahrenheit, which is unrelated.
4. Friday (schedule code)
Units & Measurements · Day of the Week Abbreviations
Friday's one-letter code on timetables, pharmacy pill organizers and class schedules, as in MWF. It is unambiguous because Friday is the only English day starting with F.
Example: Discussion section F 1:00 to 1:50 in the library seminar room.
Some schedule systems use Fr, matching the iCalendar code FR. Universities that run MWF courses in 50-minute periods often keep Friday afternoons light for labs and recitations. On grade reports F instead means a failing grade, and in temperatures it means Fahrenheit.
5. Fluorine
Science & Engineering · Chemical Element Abbreviations
The most electronegative and most chemically reactive element, fluorine (atomic number 9) is a pale yellow halogen gas that attacks glass and ignites many metals. Its compounds are everywhere: fluoride in toothpaste and drinking water, nonstick PTFE coatings, refrigerants and the uranium hexafluoride used for enrichment.
Example: Municipal water samples averaged 0.7 mg/L F, matching the recommended level for community fluoridation.
Several chemists were injured trying to isolate it; Henri Moissan finally succeeded in 1886 by electrolyzing potassium fluoride dissolved in hydrogen fluoride, earning the 1906 Nobel Prize in Chemistry. The name comes from the mineral fluorite, from Latin fluere (to flow), because fluorite was added to ores as a flux in smelting. Fluorite also gave its name to fluorescence.
6. Federal Reporter (F.)
Law & Legal · Legal Citation Abbreviations
West reporter publishing decisions of the federal courts of appeals; its first series, cited simply as F., covers 1880 to 1924 and also printed many opinions of the old federal circuit and district courts. Later series are cited F.2d, F.3d and F.4th.
Example: Taft's antitrust opinion in Addyston Pipe, 85 F. 271 (6th Cir. 1898), is still taught in law schools.
The Federal Reporter was part of West's National Reporter System, which began in 1879. Its first series closed after 300 volumes. Lower federal decisions from before 1880 are collected in Federal Cases (F. Cas.). District court opinions moved to the Federal Supplement in 1932, leaving the Federal Reporter to the courts of appeals.
7. Forte (f)
Arts & Entertainment · Music Abbreviations
Dynamic marking meaning loud. Composers combine it with other signs, such as sf or sfz (sforzando) for a sudden accent, and fp (forte-piano) for a loud attack followed immediately by softness.
Example: The brass entry at f should be strong but not harsh.
Italian for "strong". Forte appears in the name of the pianoforte. Dynamics are interpreted in context, so forte in a string quartet differs from forte in a brass band.
8. Femto- (quadrillionth) (f)
Units & Measurements · Metric and SI Unit Abbreviations
Femto- shrinks a unit by a factor of 10^15. It describes femtosecond laser pulses used in eye surgery and ultrafast chemistry, and the femtometer, about the size of a proton, which nuclear physicists call a fermi.
Example: The laser emits pulses lasting about 100 fs, short enough to cut tissue without heating it.
Adopted in 1964 together with atto-; the name comes from Danish and Norwegian femten, fifteen, for the exponent. Femtosecond lasers cut the corneal flap in bladeless LASIK. The 1999 Nobel Prize in Chemistry went to Ahmed Zewail for femtochemistry, the study of reactions on this time scale.
9. And the following (page) (f.)
Writing & Everyday · Citation and Bibliography Abbreviations
Indicates that a reference covers the page cited and the one after it, as in "p. 45f." It is the singular counterpart of ff., which covers several following pages.
Example: The definition and its first example appear on p. 212f. of the second volume.
Style guides now prefer an exact range such as "pp. 212-13," which is clearer. In manuscript citations, f. also abbreviates folio, as in "f. 23r." In music, f marks forte (loud), and in mathematics f(x) denotes a function.
Related abbreviations
More engineering unit abbreviations
- CRI – Color Rendering Index
- dB – Decibel
- dBA – A-weighted decibels
- dBm – Decibel-milliwatts
- fc – Foot-candle
- fpm – Feet per minute
- fps – Feet per second
- ft-lb – Foot-pound
See all 103 engineering unit abbreviations →
More statistics abbreviations
- DOE – Design of experiments
- EDA – Exploratory data analysis
- EFA – Exploratory factor analysis
- EM – Expectation-maximization
- FDR – False discovery rate
- FPR – False positive rate
- GARCH – Generalized autoregressive conditional heteroskedasticity
- GLM – Generalized linear model
See all 88 statistics abbreviations →
This entry is for general education and is not legal advice. Abbreviation use varies between institutions; always confirm in context.