Webster's Revised Unabridged Dictionary · 1913

Acyclic

Acyclic , adjective

[Prefix a- not + cyclic.]

(Botany) Not cyclic; not disposed in cycles or whorls
(a)
(Botany) Of a flower, having its parts inserted spirally on the receptacle.
(b)
(Botany) Having an open-chain structure; aliphatic.