The Collaborative International Dictionary of English v.0.48:
bimodal \bimodal\ adj. (Statistics) having or occurring with two modes[9]; having two maxima; -- of a curve or distribution. unimodal [WordNet 1.5]WordNet (r) 3.0 (2006):
bimodal adj 1: of a distribution; having or occurring with two modes [ant: unimodal]