Arranging is a process of putting things in order or organizing them in a certain way. The opposite of arrange is disarrange, which means to mess up or to put in disorderly fashion. It is a process of disrupting the order of things. Another antonym for arrange is jumble, which means to mix or scramble in a confused way.
A third antonym is scatter, which means to spread things over a wide area. It is the opposite of arranging things in one place. Disorder is also an antonym, which refers to the state of being unorganized or chaotic. The last antonym for the word arrange is mess up, which means to make something untidy or unclean.