pooch

A dog.

A dog of mixed breed; a mongrel.

A bulge, an enlarged part

“There's a pooch in the plastic where it got too hot.”

A distended or swelled condition.

“Her left sleeve has more pooch at the shoulder than the right.”

To distend, to swell or extend beyond normal limits; usually used with out.

“Inflate that tire too much and the tube may pooch out of the cut in the sidewall.”