I. adjective Date: 1826 having three focal lengths, II. noun Date: 1899 eyeglasses with ~ lenses, a ~ glass or lens
TRIFOCAL
Meaning of TRIFOCAL in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012