He assumed that I was waiting for winners over by the squirt guns,
and then slipping a fifty to some guy who didn't realize how a giant stuffed animal could change the world's perception of him – source
I guessed that someone was waiting for winners who had won the squirt guns game using squirt guns. but it is odd in my opinion. So,i don't know why,how 'by' did be used in sentence.
Best Answer
"Over by" is a construction that means "over there, next to".
Over, among its many meanings, is an adverb meaning "across a space or distance".
By, in this case, means "in proximity to", or "near to" (not "through the agency or instrumentality of", in this case) - see the very first definition at the link.
So the speaker is saying that the other person assumed he would be waiting at some distance, next to the squirt guns.