probably from H5719 in the original sense of slender (i.e. a spear); his spear.
First appearance
2Sam 23:8 These be the names of the mighty men whom David had: The Tachmonite that sat in the seat, chief among the captains; the same was Adino the Eznite: he lift up his spear against eight hundred, whom he slew at one time. (KJV)
