Fermat's Last Theorem

A fractional linear transformation, or Möbius transformation

An acronym (for "Friendship, Love, and Truth") sometimes seen on tombstones, signifying membership in the Oddfellows

Fermat's little theorem

Fairlight, a warez release group

Front de Libération du Tchad or Liberation Front of Chad

Federación Libre de Trabajadores

Finger Lakes Trail, system of hiking trails in upstate New York

Fédération Luxembourgeoise de Tennis, the governing body for tennis in Luxembourg

Fms-related tyrosine kinase 1, a protein