There are 2 definitions of fs in English:

fs1

Syllabification: fs

abbreviation

Femtosecond.

Definition of fs in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day hypnopompic
Pronunciation: ˌhɪpnə(ʊ)ˈpɒmpɪk
adjective
relating to the state immediately preceding waking up

There are 2 definitions of fs in English:

FS2

Line breaks: FS

Entry from British & World English dictionary

abbreviation

(In the UK) Flight Sergeant.

Definition of fs in:

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day hypnopompic
Pronunciation: ˌhɪpnə(ʊ)ˈpɒmpɪk
adjective
relating to the state immediately preceding waking up