Emily Dickinson Lexicon

RE-CIP'RO-CAL, a. [L. reciprocus; Sp. and It. reciproco; Fr. reciproque.]

1. Acting in vicissitude or return; alternate. Corruption is reciprocal to generation. – Bacon.
2. Mutual; done by each to the other; as, reciprocal love; reciprocal benefits or favors; reciprocal duties; reciprocal aid.
3. Mutually interchangeable. These two rules will render a definition reciprocal with the thing defined. – Watts. Reciprocal terms, in logic, those terms that have the same signification, and consequently are convertible and may be used for each other. – Encyc. Reciprocal quantities in mathematics, are those which, multiplied together, produce unity. – Encyc. Reciprocal figures, in geometry, are those which have the antecedents and consequents of the same ratio in both figures. – Encyc. Reciprocal ratio, is the ratio between the reciprocals of two quantities; as, the reciprocal ratio of 4 to 9, is that of 1/4 to 1/9.