an acid salt of hydrofluoric acid containing the group HF 2 -, as ammonium bifluoride, NH 4 HF 2.
Chiefly Optics. having two foci. (of an eyeglass or contact lens) having two portions, one for near and one for far vision. bifocals, bifocal eyeglasses or contact lenses. Historical Examples Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 1 “Franciscans” to “French Language” Various Parallel Paths Thomas William Rolleston adjective (optics) having two different focuses relating […]
capable of being folded into two parts, as with leaves that are hinged together: a bifold door; bifold shutters. Historical Examples Hints on cheese-making Thomas Day Curtis
having two leaves. adjective having only two leaves adj.
having two leaflets. adjective (of compound leaves) consisting of two leaflets