• (letter name) IPA: /ɛf/
• (phoneme) IPA: /f/

1. Letter of the English alphabet

f

1. (printing, abbreviation) Folio, paper and book size (10"-12.5" x 15"-20")
2. (euphemistic) fuck

   What the f do you think you're doing?

3. Alternative form of f.

• (folio paper and book size) F, fo

• Russian: ж

1. Alternative letter-case form of F#English|F

• IPA: /ɛf/

1. Letter of the English alphabet
   • 1945 August 17, George Orwell [pseudonym; Eric Arthur Blair], chapter 3, in Animal Farm: A Fairy Story, London: Secker & Warburg, OCLC 3655473 ↗:

     On several occasions, indeed, he did learn E, F, G, H, but by the time he knew them, it was always discovered that he had forgotten A, B, C, and D.

f (not comparable)

1. Abbreviation of false#English|false.
2. Abbreviation of female#English|female.
3. (philately) Abbreviation of fine#English|fine.

f (plural fs)

1. An academic grade, specifically —
   1. A failing grade, with the next best grade being either a D or an E (some institutions issue Es instead of Fs).
   2. (UK) A grade lower than E but higher than G.
2. A grade of black-lead pencil (originally an abbreviation of fine).
3. In the American Library Association, a folio-sized book, over 30 cm in height.
4. Abbreviation of fellow#English|fellow, as in F.G.S. or F.R.S.
5. (nautical) Abbreviation of fog#English|fog, as in a ship's log.
6. (US, meteorology) Initialism of Fujita (followed by a number when used in a rating on the Fujita scale and indicating the intensity of a tornado).

   the F-scale ; an F3 tornado

7. Initialism of function#English|function (followed by a number when used on or referencing a function key of a computer keyboard).

   Press F1 for help.

1. Abbreviation of various proper names.
2. Abbreviation of Fahrenheit#English|Fahrenheit.
3. Abbreviation of Father#English|Father, as a title given to priests.

   Synonyms: Fr

4. Abbreviation of French#English|French.
5. Abbreviation of Friday#English|Friday.

   Synonyms: Fri

f

1. (euphemistic) Initialism of fuck#English|fuck.

1. (internet slang) Used to profess respect for a deceased person, or for something that has been lost.
2. (internet slang) Used to express regret or disappointment about an unfortunate event or piece of information.