The Austronesian Comparative Dictionary

*kepay kepay to flap (wings, fins of fish, etc.)

PWMP kepay kepay to flap (wings, fins of fish, etc.)

WMP
Casiguran Dumagat kepay-kepay flap, wave (of the flapping of a bird's wings, or the waving back and forth of a fish's pectoral fins)
Iban kepai-kepai moving, waving, flapping (as leaves, wings)
Bikol mag-kupáy to swim by paddling with the hands
mag-kupáy-kupáy to motion with the hands; to beckon