superquintus

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

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

one fifth as much more (i. e. which bears to another the ratio of 6 to 5): numerus, Boëth. Arithm. 1, 24; Mart. Cap. 7, § 761 sq.