par·​fo·​cal ˌpär-ˈfō-kəl How to pronounce parfocal (audio)
: being or having lenses or lens sets (such as eyepieces) with the corresponding focal points all in the same plane
parfocality noun
parfocalize transitive verb

Word History


Latin par equal + English focal

First Known Use

circa 1886, in the meaning defined above

Time Traveler
The first known use of parfocal was circa 1886

Dictionary Entries Near parfocal

Cite this Entry

“Parfocal.” Dictionary, Merriam-Webster, Accessed 26 Sep. 2023.

Medical Definition


par·​fo·​cal (ˈ)pär-ˈfō-kəl How to pronounce parfocal (audio)
: having corresponding focal points all in the same plane : having sets of objectives or eyepieces so mounted that they may be interchanged without varying the focus of the instrument (as a microscope) with which they are used
parfocality noun
plural parfocalities
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!