Definition of vag:
(n) :
(US slang, chiefly vulgar) Vagina (or, by extension, vulva).
(n) :
(automotive) The Volkswagen group.
(v) :
(transitive, slang) To arrest somebody as a vagrant.
(n) :
(UK, dated, dialect, Devon) Turf used as fuel.
(v) :
(UK, dated, dialect, Devon) To flap; to blow in the wind.
(v) :
(UK, archaic, dialect, Devon) To drag; to trail on the ground.