megahertz vs Mc

megahertz and Mc both are nouns.

Word	Noun	Adjective	Verb	Adverb
megahertz	Yes	No	No	No
Mc	Yes	No	No	No

As nouns, megahertz and Mc are synonyms defined as:

Other synonyms of megahertz include megacycle, megacycle per second, MHz.

megahertz (noun)	Mc (noun)
one million periods per second	one million periods per second