קֶשֶׁת qesheth (H7198)

a bow, forshooting (hence, figuratively, strength) or the iris

1) bow 1a) bow (for hunting, battle) 1b) bowmen, archers 1c) bow (fig. of might) 1d) rainbow

from קָשָׁה (H7185) in the original sense (of קוֹשׁ (H6983)) of bending;