<p><strong>Adjective:</strong></p><ul><li>Chiefly Optics.</li><li>Having two foci.</li><li>(Of an eyeglass or contact lens) having two portions, one for near and one for far vision.</li></ul><p><strong>Noun:</strong></p><ul><li>Bifocals, bifocal eyeglasses or contact lenses.</li></ul>