ex libris vs bookplate

ex libris and bookplate both are nouns.

Word	Noun	Adjective	Verb	Adverb
ex libris	Yes	No	No	No
bookplate	Yes	No	No	No

As nouns, ex libris and bookplate are synonyms defined as:

ex libris and bookplate: a label identifying the owner of a book in which it is pasted

ex libris (noun)	bookplate (noun)
a label identifying the owner of a book in which it is pasted	a label identifying the owner of a book in which it is pasted