The Collaborative International Dictionary of English v.0.48:
Gemel \Gem"el\, a. [OF. gemel twin, F. jumeau, L. gemellus twin, doubled, dim. of geminus. See Gemini, and cf. Gimmal.] (Her.) Coupled; paired. [1913 Webster] Bars gemel (Her.), two barrulets placed near and parallel to each other. [1913 Webster]