mil·i·tate \ˈmiləˌtāt, usu -ād.+V\intransitive verb (-ed/-ing/-s) Etymology: Latin militatus, past participle of militare, from milit-, miles soldier; perhaps akin to Greek homilos assembly, Sanskrit melā 1.obsolete a.: to serve as a soldier : engage in warfare b.: to fight for a cause or a principle 2.: to have weight or effect < facts militate against this opinion > < cultural unity has tended to militate … in favor of political independence — G.T.Rowles >