tu'nic

A coat, an investing membrane; in botany, a skin or covering membrane, such as the testa of a seed, or a thick or thin separable layer, such as one of the coats of an onion, choroid t. The choroid membrane, external elastic t. See external elastic coat, under coat, inner muscular t. of the epididymis. Of Kolliker, a layer of muscular ti ue at the back of the testis and epididymis, beneath the fascia propria and opposite the lower two thirds of the testis, internal elastic t„ See _ internal elastic _ coat, under coat. vaginal t. See tunica vaginal is, under tunica. [Lat, tunica, a long Roman undergarment.]