The Collaborative International Dictionary of English v.0.48:
one-year \one-year\ adj. 1. completing its life cycle within a year. [prenominal] [WordNet 1.5]WordNet (r) 3.0 (2006):
one-year adj 1: completing its life cycle within a year; "a border of annual flowering plants" [syn: annual, one-year] [ant: biennial, perennial, two-year]