trifocal

1 of 2

adjective

tri·​fo·​cal (ˌ)trī-ˈfō-kəl 

: having three focal lengths

trifocal

2 of 2

noun

1

trifocals plural : eyeglasses with trifocal lenses

2

: a trifocal glass or lens

Word History

First Known Use

Adjective

1826, in the meaning defined above

Noun

1899, in the meaning defined at sense 1

Medical Definition

trifocal

1 of 2 adjective

tri·​fo·​cal (ˈ)trī-ˈfō-kəl 

1

: having three focal lengths

2

of an eyeglass lens : having one part that corrects for near vision, one for intermediate vision (as at arm's length), and one for distant vision

trifocal

2 of 2 noun

1

: a trifocal glass or lens

2

trifocals plural : eyeglasses with trifocal lenses