combining vs blend

combining and blend both are nouns.

Word	Noun	Adjective	Verb	Adverb
combining	Yes	No	No	No
blend	Yes	No	Yes	No

As nouns, blend is a hyponym of combining; that is, blend is a word with a more specific, narrower meaning than combining:

combining (noun)	blend (noun)
the act of combining things to form a new whole	the act of blending components together thoroughly
an occurrence that results in things being united	a new word formed by joining two others and combining their meanings
	an occurrence of thorough mixing

combining (verb)	blend (verb)
	mix together different elements
	combine into one
	blend or harmonize