TRIFOCAL


Meaning of TRIFOCAL in English

I. (ˌ)trī-ˈfō-kəl adjective

Date: 1826

: having three focal lengths

II. noun

Date: 1899

1. plural : eyeglasses with trifocal lenses

2. : a trifocal glass or lens

Merriam-Webster's Collegiate English vocabulary.      Энциклопедический словарь английского языка Merriam Webster.