|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|1.||experienced or expressed by each of two or more people or groups about the other; reciprocal: mutual distrust|
|2.||common to or shared by both or all of two or more parties: a mutual friend; mutual interests|
|3.||denoting an insurance company, etc, in which the policyholders share the profits and expenses and there are no shareholders|
|[C15: from Old French mutuel, from Latin mūtuus reciprocal (originally: borrowed); related to mūtāre to change]|
|usage The use of mutual to mean common to or shared by two or more parties was formerly considered incorrect, but is now acceptable. Tautologous use of mutual should be avoided: cooperation (not mutual cooperation) between the two countries|
"The essence of its meaning is that it involves the relation x is or does to y as y to x; & not the relation, x is or does to z as y to z" [Fowler]Mutual Admiration Society (1851) seems to have been coined by Thoreau. Mutual fund is recorded from 1950.