I. WORDS EXPRESSING ABSTRACT RELATIONS

II. RELATION

1. ABSOLUTE RELATION; RELATIONS

[Double or reciprocal relation.] Correlation.

[Nouns] reciprocalness; reciprocity, reciprocation; mutuality, correlation, interdependence, connection, link, association; interchange [more]; exchange, barter.

[Verbs] reciprocate, alternate; interchange [more]; exchange; counterchange.

[Adjectives] reciprocal, mutual, commutual, correlative; alternate; interchangeable; international; complemental, complementary.

[Adverbs] mutatis mutandis; vice versa; each other, one another; by turns [more]; reciprocally.

[Phrases] "happy in our mutual help" [Milton].