supertertius

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

sŭper-tertĭus, a, um, adj.; of a number,

one third as much more (i.e. that bears to another the ratio of 4 to 3): numerus, a transl. of the Gr. ἐπίτριτον, Censor. de Die Nat. 10, 8; 10, 11; Mart. Cap. 7, § 761 sq.