A "blunt object" refers to something that is not sharp or pointed. It usually describes a tool or weapon that has a flat or rounded end, making it less likely to cut or penetrate. Full definition
This occurs after a direct impact to the muscle, usually from a hard, blunt object such as a hard ball or an opponents elbow! (sportsinjuryclinic.net)
For the sake of my forehead and yours, consider these essential components of engaging all learners — even the ones teasing you or throwing blunt objects at your head. (corwin-connect.com)