megahit vs smasher

megahit and smasher both are nouns.

Word	Noun	Adjective	Verb	Adverb
megahit	Yes	No	No	No
smasher	Yes	No	No	No

As nouns, smasher is a hypernym of megahit; that is, smasher is a word with a broader meaning than megahit:

megahit: an unusually successful hit with widespread popularity and huge sales (especially a movie or play or recording or novel)
smasher: a conspicuous success

Other hypernyms of megahit include bang, hit, smash, strike.

megahit (noun)	smasher (noun)
an unusually successful hit with widespread popularity and huge sales (especially a movie or play or recording or novel)	a conspicuous success
	a very attractive or seductive looking woman
	a person who smashes something