"Kapay-Kapay" is a word in HILIGAYNON

kapáy-kápay - To flutter, flop, slap, clap,
flap the wings, strike the water with the
palms of the hands as in swimming, to
swing or vibrate (said of anything with a
broad surface). Nagakapáykápay lang ang
píspis sa hángin. The bird is flapping its
wings in the air. (cf. kapákápa).