Reversible describes something that can be changed back to its original state or condition, like nothing ever happened. When you fold a piece of paper, that's reversible because you can unfold it and make it flat again. When you scramble an egg, that's not reversible: there's no way to get it back into the shell as a raw egg.

In science, reversible reactions can go forward and backward. If you dissolve sugar in water, you can reverse the process by evaporating the water to get your sugar crystals back. Compare this to burning wood, which is irreversible: once wood becomes ash and smoke, you can't turn it back into wood.

The word also describes clothing designed to be worn either way. A reversible jacket might be blue on one side and red on the other, giving you two looks in one piece of clothing. You simply turn it inside out to change the color.

Understanding whether something is reversible matters when making decisions. Choosing a nickname might be reversible if people will let you change it, but getting a bad reputation is much harder to reverse. Smart planners think ahead: “If this doesn't work out, can I reverse my decision?”