• synonyms


[ trahy-hee-druh l ]
/ traɪˈhi drəl /

adjective Geometry.

having, or formed by, three planes meeting in a point: a trihedral angle.


a trihedron.

Nearby words

trigram, trigraph, trigraphic, trigère, trihalomethane, trihedral, trihedron, trihydrate, trihydric, trihydric alcohol, trihydroxy

Origin of trihedral

First recorded in 1780–90; tri- + -hedral
Related formssub·tri·he·dral, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for trihedral

  • A triangle and a trihedral angle are therefore reciprocal figures.

    Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6|Various
  • The angle between two planes is termed dihedral, between three trihedral, between any number more than three polyhedral.

British Dictionary definitions for trihedral


/ (traɪˈhiːdrəl) /


having or formed by three plane faces meeting at a point


a figure formed by the intersection of three lines in different planes

Word Origin for trihedral

C18: from tri- + Greek hedra base, seat + -al 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012