f

f 1 or F  (ĕf)
n. pl. f's or F's also fs or Fs
1. The sixth letter of the modern English alphabet.
2. Any of the speech sounds represented by the letter f.
3. The sixth in a series.
4. Something shaped like the letter F.
5. F A grade that indicates failing status.
6. Music
a. The fourth tone in the scale of C major or the sixth tone in the relative minor scale.
b. A key or scale in which F is the tonic.
c. A written or printed note representing this tone.
d. A string, key, or pipe tuned to the pitch of this tone.