'Tunic' definitions:

Definition of 'tunic'

noun

An enveloping or covering membrane or layer of body tissue [syn: tunic, tunica, adventitia]

noun

Any of a variety of loose fitting cloaks extending to the hips or knees

From: GCIDE

Tunic \Tu"nic\ (t[=u]"n[i^]k), n. [L. tunica: cf. F. tunique.] [1913 Webster]
1. (Rom. Antiq.) An under-garment worn by the ancient Romans of both sexes. It was made with or without sleeves, reached to or below the knees, and was confined at the waist by a girdle. [1913 Webster]
2. Any similar garment worn by ancient or Oriental peoples; also, a common name for various styles of loose-fitting under-garments and over-garments worn in modern times by Europeans and others. [1913 Webster]
3. (R. C. Ch.) Same as Tunicle. [1913 Webster]
4. (Anat.) A membrane, or layer of tissue, especially when enveloping an organ or part, as the eye. [1913 Webster]
5. (Bot.) A natural covering; an integument; as, the tunic of a seed. [1913 Webster]
6. (Zool.) See Mantle, n., 3 (a) . [1913 Webster]