quinquiplicate

† quinˈquiplicate, v. Obs. rare^—0.

[f. ppl. stem of L. quinquiplicāre: cf. quadruplicate v.]

‘To multiply by fives, to double five times’ (Blount Glossogr. 1656). So † quinquipliˈcation, ‘a making four times double’ (Phillips, 1678).