The Collaborative International Dictionary of English v.0.48:
Bifocal \Bi"fo`cal\, n. [Pref. bi-+ focal.] a bifocal lens. [PJC]The Collaborative International Dictionary of English v.0.48:
Bifocal \Bi"fo`cal\, a. [Pref. bi-+ focal.] Having two foci, as some spectacle lenses. [Webster 1913 Suppl.]WordNet (r) 3.0 (2006):
bifocal adj 1: having two foci; "bifocal eyeglasses"