soft palate vs velum

soft palate and velum both are nouns.

Word	Noun	Adjective	Verb	Adverb
soft palate	Yes	No	No	No
velum	Yes	No	No	No

As nouns, soft palate and velum are synonyms defined as:

soft palate and velum: a muscular flap that closes off the nasopharynx during swallowing or speaking

soft palate (noun)	velum (noun)
a muscular flap that closes off the nasopharynx during swallowing or speaking	a muscular flap that closes off the nasopharynx during swallowing or speaking
	a membranous covering attached to the immature fruiting body of certain mushrooms