FL Definition

abbreviation
Foot-lambert.
American Heritage
Florin(s)
Webster's New World
Flankerback.
American Heritage
Floor.
Webster's New World
(he or she) Flourished.
Webster's New World
symbol
Flerovium.
Webster's New World

(metrology) Symbol for the femtoliter (femtolitre), an SI unit of fluid measure equal to 10−15 liters (litres).

Wiktionary