patch ‧ y /ˈpætʃi/ BrE AmE adjective
1 . happening or existing in some areas but not in others:
patchy fog
2 . not complete enough to be useful:
His knowledge of French remained pretty patchy.
There is only patchy evidence of the animal’s existence.
3 . especially British English good in some parts but bad in others:
I thought the performance was patchy.
—patchiness noun [uncountable]