flutterboard in English dictionary flutterboard Meanings and definitions of "flutterboard" (US) a buoyancy board made of foam, used to support the body when in water. noun (US) a buoyancy board made of foam, used to support the body when in water. more Grammar and declension of flutterboard flutterboard ( plural flutterboards) flutterboard (plural flutterboards) more Sample sentences with "flutterboard" Declension Stem Try again Authors