Reciprocal describes something that goes both ways, like a two-way street where traffic flows in both directions. When you have a reciprocal friendship, you both care about each other equally. You listen when your friend needs to talk, and your friend listens when you need support. You help each other, share with each other, and make time for each other.

The word appears in many contexts. Countries might sign a reciprocal trade agreement, meaning each nation reduces tariffs for the other. A gym might have a reciprocal membership with other gyms, so members can use any location. Scientists talk about organisms in reciprocal relationships, like bees and flowers: bees get nectar while flowers get pollinated.

In mathematics, a reciprocal is what you get when you flip a fraction upside down. The reciprocal of 3/4 is 4/3. The reciprocal of 5 (which is really 5/1) is 1/5. When you multiply any number by its reciprocal, you always get 1.

The key idea is exchange and balance. Reciprocal suggests fairness and mutual benefit. If someone invites your family to dinner, you might reciprocate by inviting them to your house.