verb (used with object), mis·han·dled, mis·han·dling.
Examples from the Web for mishandle
That misstep turned the narrative into how Romney would handle (or mishandle) a crisis, rather than keeping the focus on Obama.
I hope they'll be all right careful of them pianos and not mishandle them so they'll get out of tune.Bucky O'Connor|William MacLeod Raine
A man hasn't many privileges in this country, but he might at least be allowed to mishandle his own rifle.Life's Handicap|Rudyard Kipling