Mutually assured destruction is a doctrine of military strategy and national security policy in which a full-scale use of nuclear weapons by two or more opposing sides would cause the complete annihilation of both the attacker and the defender.

They formed a mutual admiration society.

I opened a new account at the mutual savings bank.

They formed their own mutual admiration societies.

Mutual savings banks offer competitive interest rates for their customers.

They agreed to work mutualy on the project.

They are mutualising their resources to achieve a common goal.

The company mutualises its resources to improve efficiency.

Companies often choose to mutualise their resources to reduce costs.