The word "straightens up" is a verb that refers to the act of making something straight or orderly. Some antonyms for "straightens up" include "messes up," "disarray," "clutter," "disorganize," "scatter," and "jumble." When you mess something up, you make it worse or put it in a state of disorder, opposite to the idea of "straightening up." Therefore, if you disarray something, you disrupt its organized state of being. Cluttering something means filling it up with unnecessary things, and disorganizing it is the act of removing its order or structure. Lastly, scattering and jumbling something is the act of making things disordered, opposite to the meaning of straightening up.