Passive participle of the same as chomesh; staunch, i.e. Able-bodied soldiers -- armed (men), harnessed.
see HEBREW chomesh
H2571. chamushim
חֲמֻשִׁים adjective plural in battle array, always this form, Exodus 13:18 (E), Joshua 1:14; 4:12 (both D), Judges 7:11 + Numbers 32:17 (JE), see חושׁ.
חמת (√ of following; meaning unknown; Mv and others, very improbably, from Arabic grow rancid, putrid; see on formation, LagBN 154).