ti vs si

ti and si both are nouns.

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

As nouns, ti and si are synonyms defined as:

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

Other synonyms of ti include te.

ti (noun)	si (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
shrub with terminal tufts of elongated leaves used locally for thatching and clothing; thick sweet roots are used as food; tropical southeastern Asia, Australia and Hawaii