mid-15c., subordinacioun "hierarchical arrangement," from Medieval Latin subordinationem (nominative subordinatio), noun of action from subordinatus (see subordinate (adj.)).
The use of expressions that make one element of a sentence dependent on another. In the following sentence, the first (italicized) clause (also called a subordinate clause) is subordinate to the second clause: “Despite all efforts toward a peaceful settlement of the dispute, war finally broke out.” (Compare coordination, dependent clause, and independent clause.)