\Re*cip"ro*cal*ly\, adv. 1. In a reciprocal manner; so that each affects the other, and is equally affected by it; interchangeably; mutually. These two particles to reciprocally affect each other with the same force. --Bentley. 2. (Math.) In the manner of reciprocals. {Reciprocally proportional} (Arith. & Alg.), proportional, as two variable quantities, so that the one shall have a constant ratio to the reciprocal of the other.