BELLYACHE is validvalid

to complain excessively [v BELLYACHED, BELLYACHES, BELLYACHING] : BELLYACHER [n]

91,393 of 196,601 in NWL2023·also valid in CSW24

a pain in the stomach [n -S] / to moan, complain [v BELLYACHED, BELLYACHING, BELLYACHES]