/buy foh"keuhl, buy"foh'-/ , adj.
1. Chiefly Optics. having two foci.
2. (of an eyeglass or contact lens) having two portions, one for near and one for far vision.
n.
3. bifocals , bifocal eyeglasses or contact lenses.
[ 1885-90, Amer.; BI- 1 + FOCAL ]