Definition of splint:
(n) :
a narrow strip of wood split or peeled off of a larger piece; a device to immobilize a body part
"1819 The fore-part of his thighs, where the folds of his mantle permitted them to be seen, were also covered with linked mail; the knees and feet were defended by splints , or thin plates of steel, ingeniously jointed upon each other"
(v) :
to apply a splint; to support one's abdomen with hands or a pillow before attempting to cough