sitter vs being

sitter and being both are nouns.

Word	Noun	Adjective	Verb	Adverb
sitter	Yes	No	No	No
being	Yes	No	No	No

As nouns, being is a hypernym of sitter; that is, being is a word with a broader meaning than sitter:

sitter: an organism (person or animal) that sits
being: a living thing that has (or can develop) the ability to act or function independently

Other hypernyms of sitter include organism.

sitter (noun)	being (noun)
a domestic hen ready to brood	a living thing that has (or can develop) the ability to act or function independently
a person engaged to care for children when the parents are not home	the state or fact of existing
an organism (person or animal) that sits
a person who poses for a painter or sculptor