abridgment vs abridgement

abridgment and abridgement both are nouns.

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

As nouns, abridgment and abridgement are synonyms defined as:

Other synonyms of abridgment include capsule, condensation.

abridgment (noun)	abridgement (noun)
a shortened version of a written work	a shortened version of a written work