Lewis Short
perna (noun F) : πέρνα.
* A haunch or ham together with the leg.
* Lit.
* Of men: is (i. e. his, militibus) pernas succidit, Enn. ap. Fest. pp. 304 and 305 (Ann. v. 279 Vahl.) (for which, in Liv. 22, 51: succisis feminibus poplitibusque).
* Transf., of things of a similar shape.
* A sea-mussel: pernae concharum generis,Plin. 32, 11, 54, § 154.
* A part of the body of a tree sticking to its suckers when pulled off: stolones cum pernā suā avelluntur, Plin. 17, 10, 13, § 67.
Charlton T. Lewis, Charles Short, A Latin Dictionary