Definition of birl:
(n) :
(Internet slang, LGBTQ) A girl of boyish appearance.
(v) :
(ambitransitive, Scotland) To spin.
(v) :
(transitive) To cause (a floating log) to rotate by treading on it.
(v) :
(transitive) To throw down a coin as one's share in a joint contribution.
(n) :
(music, bagpipes) A type of grace note movement that quickly switches between low-A and low-G several times, producing a low rippling sound.
(v) :
Alternative form of birle (“to drink, carouse”). [(Scotland, obsolete) To pour a drink (for).]