mutual

adj. 共同的；相互的，彼此的

中文词源

mutual 相互的

来自阿拉伯语muttus,交换的，相互的，来自PIE*mei,改变，交换，词源同mutable,common.

mutual (adj.): late 15c., originally of feelings, from Middle French mutuel (14c.), from Latin mutuus "reciprocal, done in exchange," from PIE root *mei- (1) "to change, exchange" (see mutable).
That is common which pertains equally to two or more persons or things.
That is mutual which is freely interchanged: mutual love, affection, hatred. The word is sometimes incorrectly used for common: our mutual friend, a phrase of very frequent occurrence, no doubt owing to the perfectly correct 'mutual friendship.'
[J.H.A. Günther, "English Synonyms Explained & Illustrated," Groningen, 1904]
Mutual Admiration Society (1851) seems to have been coined by Thoreau. Mutual fund is recorded from 1950. The Cold War's mutual assured destruction attested from 1966. (Assured destruction was an early 1960s term in U.S. military policy circles in reference to nuclear weapons as a deterrent, popularized c. 1964 by Robert McNamara, U.S. Secretary of Defense under Lyndon Johnson, e.g. statement before House Armed Services Committee, Feb. 18, 1965; the mutual perhaps first added by Donald Brennan, conservative defense analyst and a public critic of the policy, who also noted the acronym MAD.)
mutual (n.): short for mutual fund, 1971; see mutual.

1. It's plain that he adores his daughter, and the feeling is mutual.: 明摆着他很喜欢自己的女儿，而且女儿也喜欢他。

2. He left the company by mutual consent last September.: 去年9月，经双方同意，他离开了公司。

3. The campaign has abounded in mutual accusations of uncivilised behaviour.: 整个活动中双方频频指责对方粗野。

4. She learned her insurance had been canceled by Pacific Mutual Insurance Company.: 她得知自己的保险已经被太平洋互助保险公司中止了。