matruelis

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

mātrŭēlis, is, m. [mater],

a mother's brother's son, a cousin-german, first-cousin on the mother's side (cf. patruelis, a father's brother's son; post class.), Dig. 48, 9, 1; Vict. de Orig. Gentis Rom. 13, 8.