ROGET THESAURUS
necessitate
Necessity
VB
lie under a necessity, befated, be doomed, be destined, in for, under the necessity of, have no choice, have no alternative, be one's fate, to be pushed to the wall to be driven into a corne, to be unable to help, destine, doom, foredoom, devote, predestine, preordain, cast a spell,
necessitate, compel.
Requirement
VB
require, need, want, have occasion for, not be able to do without, not be able to dispense with, prerequire, render necessary,
necessitate, create a, necessity for, call for, put in requisition, make a requisition, stand in need of, lack, desiderate, desire, be necessary Adj.
Compulsion
VB
compel, force, make, drive, coerce, constrain, enforce,
necessitate, oblige, force upon, press, cram down the throat, thrust down the throat, force down the throat, say it must be done, make a point of, insist upon, take no denial, put down, dragoon, extort, wring from, squeeze, put on the squeeze, put on the screws, turn on the screw, drag into, bind, bind over, pin down, tie down, require, tax, put in force, commandeer, restrain.