myofibrilla vs filament

myofibrilla and filament both are nouns.

Word	Noun	Adjective	Verb	Adverb
myofibrilla	Yes	No	No	No
filament	Yes	No	No	No

As nouns, filament is a hypernym of myofibrilla; that is, filament is a word with a broader meaning than myofibrilla:

myofibrilla: one of many contractile filaments that make up a striated muscle fiber
filament: a very slender natural or synthetic fiber

Other hypernyms of myofibrilla include fibril, strand.

myofibrilla (noun)	filament (noun)
one of many contractile filaments that make up a striated muscle fiber	a thin wire (usually tungsten) that is heated white hot by the passage of an electric current
	a threadlike structure (as a chainlike series of cells)
	the stalk of a stamen
	a very slender natural or synthetic fiber