fs

See also: Fs, FS, fS, f's, F's, and ␜

Translingual

Symbol

fs

2. (metrology) Symbol for femtosecond, an SI unit of time equal to 10⁻¹⁵ seconds.

English

Etymology 1

Noun

fs

1. plural of f

Usage notes

• Opinions vary regarding the use of apostrophes when forming the plurals of letters of the alphabet. New Fowler’s Modern English Usage, after noting that the usage has changed, states on page 602 that “after letters an apostrophe is obligatory.” The 17th edition of The Chicago Manual of Style states in paragraph 7.15, “To aid comprehension, lowercase letters form the plural with an apostrophe and an s”. The Oxford Style Manual on page 116 advocates the use of common sense.

Etymology 2

Prepositional phrase

fs

1. (text messaging) Abbreviation of for sure.

Anagrams

• S. F., S.F., SF, Sf, s-f, sf