The word reciprocal can have different meanings:

• In mathematics, the reciprocal of a number is its multiplicative inverse, i.e. the number such that their product yield the number .
• In navigation a reciprocal bearing is the bearing that will take you in the reverse direction to that of the original bearing.
• In the humanities and social sciences, an interaction between actors is said to be reciprocal when each action or favour given by one party is matched by another in return.
• See also the principle of reciprocity in international negotiations .