Webster’s Revised Unabridged Dictionary · 1913
Quinary
Qui′na·ry (kwī′nȧ·ry̆), a. [L. quinarius, from quini five each, akin to quinque five: cf. F. quinaire. See Five.] Consisting of five; arranged by fives. Boyle.
Quinary system (Zoöl.), a fanciful classification based on the hypothesis that each group contains five types.