The pipsquack was a rare and elusive bird being searched for by Tom and Jerry in the guise of nature photographers on the episode titled "Hold That Pose" from "The Tom & Jerry Show" circa 1975. The legendary bird was theretofore never seen, but known only by it's intensely annoying, loud, and oft-repeated call of PIPSQUACK!, until the end of the episode, when, upon finally discovering the bird, a cacophony of pipsquacks emerge from the jungle.

The call of the pipsquack is so irritating that is is burned into the memory of most Gen-Xers, despite them having usually forgotten the show that it was featured on.

PIPSQUACK!

Literally everyone, ever. Including the writer of this definition.

It is from a old cartoon called george of the jungle. You use it as a way to say hello or to test someone to see if they are paying attention. You say "pipsquak!" and the person you are saying it to says "BIRD!". That is if they are on board with what you are saying. Like a inside joke almost. Kind of like marco polo.