n.1 a a close-fitting short coat of police or military etc. uniform. b a loose, often sleeveless garment usu. reaching to about the knees, as worn in ancient Greece and Rome. c any of various loose, pleated dresses gathered at the waist with a belt or cord. d a tunicle.
2 Zool. the rubbery outer coat of an ascidian etc.
3 Bot. a any of the concentric layers of a bulb. b the tough covering of a part of this.
4 Anat. a membrane enclosing or lining an organ.
Etymology: F tunique or L tunica