si vs te

si and te both are nouns.

Word	Noun	Adjective	Verb	Adverb
si	Yes	No	No	No
te	Yes	No	No	No

As nouns, si and te are synonyms defined as:

si and te: the syllable naming the seventh (subtonic) note of any musical scale in solmization

Other synonyms of si include ti.

si (noun)	te (noun)
the syllable naming the seventh (subtonic) note of any musical scale in solmization	the syllable naming the seventh (subtonic) note of any musical scale in solmization