Wiktionary
strap up
vb. (context transitive English) To fasten with a strap
Usage examples of "strap up".
I shall take the strap up then to your wrists, so that the knot will be where you can reach it neither with your fingers or teeth.
Hollice checked his charge and hitched the strap up onto his shoulder.
She didn't see the fighter approach, but the impact jerked the strap up against her cracked ribs and turned her bones to jelly.
Just loosen the cinch -- that narrow leather strap up by the bottom edge of the saddle.
He lifted the sheath's strap up from his shoulder, to show that it was not adhering unnaturally.