solfa syllable vs sol

solfa syllable and sol both are nouns.

Word	Noun	Adjective	Verb	Adverb
solfa syllable	Yes	No	No	No
sol	Yes	No	No	No

As nouns, sol is a hyponym of solfa syllable; that is, sol is a word with a more specific, narrower meaning than solfa syllable:

solfa syllable: one of the names for notes of a musical scale in solmization
sol: the syllable naming the fifth (dominant) note of any musical scale in solmization

Other hyponyms of solfa syllable include do, doh, ut, ray, re, mi, fa, so, soh, la, lah, si, te, ti.

solfa syllable (noun)	sol (noun)
one of the names for notes of a musical scale in solmization	the syllable naming the fifth (dominant) note of any musical scale in solmization
	a colloid that has a continuous liquid phase in which a solid is suspended in a liquid