semibreve vs musical note

semibreve and musical note both are nouns.

Word	Noun	Adjective	Verb	Adverb
semibreve	Yes	No	No	No
musical note	Yes	No	No	No

As nouns, musical note is a hypernym of semibreve; that is, musical note is a word with a broader meaning than semibreve:

semibreve: a musical note having the longest time value (equal to four beats in common time)
musical note: a notation representing the pitch and duration of a musical sound

Other hypernyms of semibreve include note, tone.

semibreve (noun)	musical note (noun)
a musical note having the longest time value (equal to four beats in common time)	a notation representing the pitch and duration of a musical sound