adjective

1. 1. done, felt, etc. by each of two or more for or toward the other or others; reciprocal mutual admiration
   2. of, or having the same relationship toward, each other or one another mutual enemies
2. shared in common; joint our mutual friend
3. designating or of a type of insurance in which the policyholders elect the directors, share in the profits, and agree to indemnify one another against loss

Etymology: LME mutuall < MFr mutuel < L mutuus, mutual, reciprocal < mutare, to change, exchange: see miss