trifocal

1 of 2

adjective

tri·​fo·​cal (ˌ)trī-ˈfō-kəl How to pronounce trifocal (audio)
: 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

Time Traveler
The first known use of trifocal was in 1826

Dictionary Entries Near trifocal

Cite this Entry

“Trifocal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trifocal. Accessed 18 Mar. 2024.

Medical Definition

trifocal

1 of 2 adjective
tri·​fo·​cal (ˈ)trī-ˈfō-kəl How to pronounce trifocal (audio)
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
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