Godan verb with 'su' ending, Transitive verb
to dump (a load of something)
あんな物を投げ下ろせば、運悪く当たった人は、ケガをする。If you throw something like that down, if someone's unlucky enough to be hit they'll be injured. to throw from a height; to throw downwards
Also written 投下ろす【なげおろす】