abridgement vs summary

abridgement and summary both are nouns.

Word	Noun	Adjective	Verb	Adverb
abridgement	Yes	No	No	No
summary	Yes	Yes	No	No

As nouns, summary is a hypernym of abridgement; that is, summary is a word with a broader meaning than abridgement:

Other hypernyms of abridgement include sum-up.

abridgement (noun)	summary (noun)
a shortened version of a written work	a brief statement that presents the main points in a concise form

abridgement (adjective)	summary (adjective)
	briefly giving the gist of something
	performed speedily and without formality