deletion vs expunction

deletion and expunction both are nouns.

Word	Noun	Adjective	Verb	Adverb
deletion	Yes	No	No	No
expunction	Yes	No	No	No

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

Other hyponyms of deletion include castration, expurgation, censoring, censorship, erasure, expunging.

deletion (noun)	expunction (noun)
the act of deleting something written or printed	deletion by an act of expunging or erasing
the omission that is made when an editorial change shortens a written passage
(genetics) the loss or absence of one or more nucleotides from a chromosome
any process whereby sounds or words are left out of spoken words or phrases