backing vs approval

backing and approval both are nouns.

Word	Noun	Adjective	Verb	Adverb
backing	Yes	No	No	No
approval	Yes	No	No	No

As nouns, approval is a hypernym of backing; that is, approval is a word with a broader meaning than backing:

Other hypernyms of backing include approving, blessing.

backing (noun)	approval (noun)
the act of providing approval and support	the formal act of approving
something forming a back that is added for strengthening	a message expressing a favorable opinion
financial resources provided to make some project possible	a feeling of liking something or someone good
	acceptance as satisfactory