[ ˌtɛtrə'hi:drən , -'hɛd- ]
■ noun ( plural tetrahedra -drə or ~s ) a solid having four plane triangular faces.
Derivatives
tetrahedral adjective
Origin
C16: from late Gk tetraedron , neut. (used asnoun) of tetraedros 'four-sided'.
[ ˌtɛtrə'hi:drən , -'hɛd- ]
■ noun ( plural tetrahedra -drə or ~s ) a solid having four plane triangular faces.
Derivatives
tetrahedral adjective
Origin
C16: from late Gk tetraedron , neut. (used asnoun) of tetraedros 'four-sided'.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004