means A perch is a spiny-finned freshwater fish (genus Perca) prized for its mild, flaky flesh — or, more loosely, any of various similar food fishes.

from From Old French 'perche', from Latin 'perca', borrowed in turn from Greek 'perke', the name for the fish. The Greek word is thought to be related to 'perknos', meaning dark-spotted or dappled — a nod to the markings along its sides, so the fish was essentially named 'the speckled one'. (Note this perch is unrelated to the other 'perch' — the bird's roost — which comes from Latin 'pertica', a pole.)