Galahad vs Sir Galahad

Galahad and Sir Galahad both are nouns.

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

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

Galahad and Sir Galahad: (Arthurian legend) the most virtuous knight of the Round Table; was able to see the Holy Grail

Galahad (noun)	Sir Galahad (noun)
(Arthurian legend) the most virtuous knight of the Round Table; was able to see the Holy Grail	(Arthurian legend) the most virtuous knight of the Round Table; was able to see the Holy Grail