M / mātrŭēlis
noun

mātrŭēlis

gen. mātrŭēlis · gender masculine · decl. 3rd
a mother's brother's son, a cousin-german, first-cousin
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.