Sir Gawain vs Gawain

Sir Gawain and Gawain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sir Gawain	Yes	No	No	No
Gawain	Yes	No	No	No

As nouns, Sir Gawain and Gawain are synonyms defined as:

Sir Gawain and Gawain: (Arthurian legend) a nephew of Arthur and one of the knights of the Round Table

Sir Gawain (noun)	Gawain (noun)
(Arthurian legend) a nephew of Arthur and one of the knights of the Round Table	(Arthurian legend) a nephew of Arthur and one of the knights of the Round Table