Mutual, a.
Etymology: [F. mutuel, L. mutuus, orig., exchanged, borrowed, lent; akin to mutare to change. See Mutable.]
1. Reciprocally acting or related; reciprocally receiving and giving; reciprocally given and received; reciprocal; interchanged; as, a mutual love, advantage, assistance, aversion, etc. Conspiracy and mutual promise. Sir T. More. Happy in our mutual help, And mutual love. Milton. A certain shyness on such subjects, which was mutual between the sisters. G. Eliot.
2. Possessed, experienced, or done by two or more persons or things at the same time; common; joint; as, mutual happiness; a mutual effort. Burke. A vast accession of misery and woe from the mutual weeping, and wailing, and gnashing of teeth. Bentley.
Note: This use of mutual as synonymous with common is inconsistent with the idea of interchange, or reciprocal relation, which properly belongs to it; but the word has been so used by many writers of high authority. The present tendency is toward a careful discrimination. Mutual, as Johnson will tell us, means something reciprocal, a giving and taking. How could people have mutual ancestors P. Harrison. Mutual insurance, agreement among a number of persons to insure each other against loss, as by fire, death, or accident. -- Mutual insurance company, one which does a business of insurance on the mutual principle, the policy holders sharing losses and profits pro rata.
Syn. -- Reciprocal; interchanged; common.
Shades of meaning
That is common to which two or more persons have the same or equal claims, or in which they have equal interest or participation; in the strictest sense, that is mutual (Latin mutare, to change) which is freely interchanged; that is reciprocal in respect to which one act or movement is met by a corresponding act or movement in return; we speak of our common country, mutual affection, reciprocal obligations, the reciprocal action of cause and effect, where the effect becomes in turn a cause. Many good writers hold it incorrect to say "a mutual friend," and insist that "a common friend" would be more accurate; but "common friend" is practically never used, because of the disagreeable suggestion that attaches to common, of ordinary or inferior. "Mutual friend" has high literary authority (of Burke, Scott, Dickens, and others), and a considerable usage of good society in its favor, the expression being quite naturally derived from the thoroughly correct phrase mutual friendship.