Mortimer vs Roger de Mortimer

Mortimer and Roger de Mortimer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Mortimer	Yes	No	No	No
Roger de Mortimer	Yes	No	No	No

As nouns, Mortimer and Roger de Mortimer are synonyms defined as:

Mortimer and Roger de Mortimer: English nobleman who deposed Edward II and was executed by Edward III (1287-1330)

Other synonyms of Mortimer include Roger Mortimer.

Mortimer (noun)	Roger de Mortimer (noun)
English nobleman who deposed Edward II and was executed by Edward III (1287-1330)	English nobleman who deposed Edward II and was executed by Edward III (1287-1330)