medevac vs medivac

medevac and medivac both are nouns.

Word	Noun	Adjective	Verb	Adverb
medevac	Yes	No	No	No
medivac	Yes	No	No	No

As nouns, medevac and medivac are synonyms defined as:

medevac and medivac: the evacuation of persons (usually by air transportation) to a place where they can receive medical care

Other synonyms of medevac include medical evacuation.

medevac (noun)	medivac (noun)
the evacuation of persons (usually by air transportation) to a place where they can receive medical care	the evacuation of persons (usually by air transportation) to a place where they can receive medical care