Origin and Etymology of parfocal
Latin par equal + English focal
First Known Use: circa 1886
Medical Definition of parfocal
: 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\-fō-ˈkal-ət-ē\play noun plural
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