Quadrennial

Adjective, Noun

quad=ren=ni=al

CIDE DICTIONARY

Quadrennial, a. [L. quadriennium a space of four years; quattuor four + annus year; cf. L. quadriennis. See Quadrate, and Annual.].

Comprising four years; as, a quadrennial period. [1913 Webster]
Occurring once in four years, or at the end of every four years; as, quadrennial games. [1913 Webster]

Quadrennial, adj.
1 lasting four years.
2 recurring every four years.

Derivative

quadrennially adv.

Etymology

as QUADRENNIUM