water pistol vs squirter

water pistol and squirter both are nouns.

Word	Noun	Adjective	Verb	Adverb
water pistol	Yes	No	No	No
squirter	Yes	No	No	No

As nouns, water pistol and squirter are synonyms defined as:

water pistol and squirter: plaything consisting of a toy pistol that squirts water

Other synonyms of water pistol include squirt gun, water gun.

water pistol (noun)	squirter (noun)
plaything consisting of a toy pistol that squirts water	plaything consisting of a toy pistol that squirts water