(politics, public policy, military) The threat of massive retaliation using nuclear weapons should a potential enemy use them first, both sides being annihilated in the event of war.

(idiomatic, derogatory) A group of two or more people, in a workplace or other social environment, who routinely express considerable esteem and support for one another, sometimes to the point of exaggeration or pretense.

A financial institution chartered by a central or regional government, without capital stock, that is nominally owned by its members, who subscribe to a common fund.

plural of mutual savings bank

plural of mutual admiration society

(formal, history) Synonym of Warsaw Pact