(esp. in European politics) cooperation, as among opposing factions, aimed at effecting a unified proposal or concerted action.
Origin: 1500–10; < F < L concertātiōn- (s. of concertātiō strife, controversy), equiv. to concertāt(us) ptp. of concertāre to contend, fight (con-con-+ certāre to contend, freq. of cernere to decide, determine, lit., to sift; cf. certain) + -iōn--ion; though influenced by F concerter (see concert) and perh. a new formation
[kon-ser-tey-shuh
n; Fr. kawn-ser-ta-syawn] 