[ trahy-foh-kuh l, trahy-foh- ]
/ traɪˈfoʊ kəl, ˈtraɪˌfoʊ- /
Optics. having three foci.
(of an eyeglass lens) having three portions, one for near, one for intermediate, and one for far vision.
trifocals, eyeglasses with trifocal lenses.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for trifocal
having three focuses
having three focal lengths
noun (traɪˈfəʊkəl, ˈtraɪˌfəʊkəl)
(plural) glasses with trifocal lenses
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