Other forms: misplaced; misplacing; misplaces
When you misplace your car keys, you can't remember where you put them. In other words, you temporarily lose them.
You can use the verb misplace when you can't find something. If you misplace your favorite coffee cup, you'll be annoyed, but if you misplace your wallet it could cause you real problems. The word implies that the object isn't gone for good, but that you unthinkingly put it down somewhere. When you combine the prefix mis-, which means "bad or wrong," and place, you get misplace — as in placing something in a bad spot!