deletion vs ellipsis

deletion and ellipsis both are nouns.

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

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

deletion: any process whereby sounds or words are left out of spoken words or phrases
ellipsis: omission or suppression of parts of words or sentences

Other hyponyms of deletion include aphaeresis, apheresis, aphesis, elision, eclipsis.

deletion (noun)	ellipsis (noun)
the act of deleting something written or printed	omission or suppression of parts of words or sentences
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