War meaning : Organized, large-scale, armed conflict between countries or between national, ethnic, or other sizeable groups, usually involving the engagement of military forces. A particular conflict of this kind. (by extension) Any conflict, or anything resembling a conflict. Instruments of war. Armed forces. A particular card game for two players, notable for having its outcome predetermined by how the cards are dealt. To engage in conflict (may be followed by "with" to specify the foe). To carry on, as a contest; to wage.