Gawain vs Sir Gawain

Gawain and Sir Gawain both are nouns.

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

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

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

Gawain (noun)	Sir 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