attender vs beholder

attender and beholder both are nouns.

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

As nouns, beholder is a hypernym of attender; that is, beholder is a word with a broader meaning than attender:

attender: someone who listens attentively
beholder: a person who becomes aware (of things or events) through the senses

Other hypernyms of attender include observer, perceiver, percipient.

attender (noun)	beholder (noun)
someone who waits on or tends to or attends to the needs of another	a person who becomes aware (of things or events) through the senses
a person who is present and participates in a meeting
someone who listens attentively