patchy

adj

1. Full of, or covered with, patches; abounding in patches.
2. Not constant or continuous; intermittent or uneven.

   “patchy clouds”

   “a patchy performance”

   “Added to these woes was the Treasury's demands for across-the-board train operator cost-cutting of broadly 10%. Passenger rail's slow, patchy and fragile recovery had the stuffing knocked out of it once more.”