sitter vs sit

sitter is a noun but sit is not a noun.

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

sitter (noun)	sit (noun)
a domestic hen ready to brood
a person engaged to care for children when the parents are not home
an organism (person or animal) that sits
a person who poses for a painter or sculptor

sitter (verb)	sit (verb)
	serve in a specific professional capacity
	be in a position in which one's upper body is largely upright and supported by one's backside
	show to a seat; assign a seat for
	take a seat
	be in session
	sit and travel on the back of animal, usually while controlling its motions
	assume a posture as for artistic purposes
	work or act as a baby-sitter
	be around, often idly or without specific purpose
	be located or situated somewhere