hypoid Syllabification: (hy·poid)Pronunciation: /ˈhīˌpoid/ (also hypoid gear)Definition of hypoid noun a bevel wheel with teeth engaging with a spiral pinion mounted at right angles to the wheel’s axis, used to connect nonintersecting shafts in vehicle transmissions and other mechanisms. Origin: 1920s: perhaps a contraction of hyperboloidhypoid in other Oxford dictionaries Definition of hypoid in the British & World English dictionary