beholder vs observer

beholder and observer both are nouns.

Word	Noun	Adjective	Verb	Adverb
beholder	Yes	No	No	No
observer	Yes	No	No	No

As nouns, beholder and observer are synonyms defined as:

beholder and observer: a person who becomes aware (of things or events) through the senses

Other synonyms of beholder include perceiver, percipient.

beholder (noun)	observer (noun)
a person who becomes aware (of things or events) through the senses	a person who becomes aware (of things or events) through the senses
	an expert who observes and comments on something