Both share a lot of meaning; The first can be defined as “shared, felt or shown by both parties” and the second as “shared together”. Based on this semantic overlap, some user manuals warn against using any form of the two words (reciprocal or reciprocal) together because they are redundant. Reciprocity is a name. The verbal form of the word is reciprocal; the adjective is reciprocal and the adverb is reciprocal. Each of these words has several meanings, some of which are similar and some of which are not. Reciprocity can mean “a mutual exchange of privileges” and is often applied to things like professional certification (neighboring states may have a mutual agreement, so the certification an employee needs is applicable to everyone). Approval can mean “sanction, approval” or simply refer to “the act or process of approval.” Latin reciprocity returning in the same way, alternately. .