concerted

(verb) contrive (a plan) by mutual agreement. Synonyms: concert.

(verb) settle by agreement. Synonyms: concert. Example: "Concert one's differences."

(adj) involving the joint activity of two or more. Synonyms: conjunct, conjunctive, cooperative. Examples: "Concerted action." "The conjunct influence of fire and strong wind." "The conjunctive focus of political opposition." "A cooperative effort." "A united effort." "Joint military activities."