1. <zoology> A genus of spinose, plectognath fishes, having the teeth of each jaw united into a single beaklike plate. They are able to inflate the body by taking in air or water, and, hence, are called globefishes, swellfishes, etc. Fishes, and sea hedgehogs.

2. <zoology> A genus of whales.

Origin: Gr. = twice +, a tooth: cf. F. Diodon.

(01 Mar 1998)