air mile vs international nautical mile

air mile and international nautical mile both are nouns.

Word	Noun	Adjective	Verb	Adverb
air mile	Yes	No	No	No
international nautical mile	Yes	No	No	No

As nouns, air mile and international nautical mile are synonyms defined as:

air mile and international nautical mile: a unit of length used in navigation; exactly 1,852 meters; historically based on the distance spanned by one minute of arc in latitude

Other synonyms of air mile include mi, mile, naut mi, nautical mile.

air mile (noun)	international nautical mile (noun)
a unit of length used in navigation; exactly 1,852 meters; historically based on the distance spanned by one minute of arc in latitude	a unit of length used in navigation; exactly 1,852 meters; historically based on the distance spanned by one minute of arc in latitude