Wiktionary
n. A pocket made of a piece of fabric by sewing it onto the outside of a garment.
WordNet
n. a flat pocket sewn to the outside of a garment
Usage examples of "patch pocket".
Craig drew the thick envelope from the patch pocket of his bush-jacket.
Jerry was beside her in a medieval-looking tunic with a most un-medieval patch pocket full of felt-tip pens.
She was wearing a navy skirt and white blouse, topped by a smart red blazer with a phony crest on the patch pocket.
Some kind of designer label ran diagonally across the right patch pocket of the jeans.
From a patch pocket he produced what appeared to be a pair of binoculars with a short whip aerial.
With her other hand she dug into the big patch pocket on her jeans.
To the growing pile of ruin, she added one of Joey's cardigan sweaters, after popping loose one bone button and almost completely detaching a sewn-on patch pocket.