The Collaborative International Dictionary of English v.0.48:
acanthoid \acanthoid\ acanthous \acanthous\adj. 1. 1 shaped like a spine or thorn Syn: spinous [WordNet 1.5]WordNet (r) 3.0 (2006):
acanthous adj 1: shaped like a spine or thorn [syn: acanthoid, acanthous, spinous]