ellipsis vs deletion

ellipsis and deletion both are nouns.

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

As nouns, deletion is a hypernym of ellipsis; that is, deletion is a word with a broader meaning than ellipsis:

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

Other hypernyms of ellipsis include omission.

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