splendour vs luster

splendour and luster both are nouns.

Word	Noun	Adjective	Verb	Adverb
splendour	Yes	No	No	No
luster	Yes	No	No	No

As nouns, splendour and luster are synonyms defined as:

Other synonyms of splendour include brilliancy, lustre, splendor.

splendour (noun)	luster (noun)
a quality that outshines the usual	a surface coating for ceramics or porcelain
the quality of being magnificent or splendid or grand	a quality that outshines the usual
	the visual property of something that shines with reflected light