THESAURUS
compulsory
absolute, binding, choiceless, coactive, compelling, compulsatory, compulsive, conclusive, constraining, decisive, decretory, dictated, driving, entailed, exigent, final, hard-and-fast, imperative, imperious, importunate, imposed, inevitable, involuntary, irresistible, irrevocable, mandated, mandatory, must, necessary, necessitous, obligatory, peremptory, prescript, prescriptive, pressing, required, restraining, ultimate, urgent, without appeal, without choice
ROGET THESAURUS
compulsory
Authority
N
authority, influence, patronage, power, preponderance, credit, prestige, prerogative, jurisdiction, right, direction, government, divine right, dynastic rights, authoritativeness, absoluteness, absolutism, despotism, jus nocendi, jus divinum, mastery, mastership, masterdom, dictation, control, hold, grasp, grip, gripe, reach, iron sway, fangs, clutches, talons, rod of empire, commission, deputy, permission, at the head, dominant, paramount, supreme, predominant, preponderant, in the ascendant, influential, arbitrary,
compulsory, stringent, at one's command, in one's power, in one's grasp, under control, in the name of, by the authority of, de par le Roi, in virtue of, under the auspices of, in the hands of, at one's pleasure, by a dash if the pen, by a stroke of the pen, ex mero motu, ex cathedra, from the chair, the gray mare the better horse, every inch a king.
Compulsion
N
compulsion, coercion, coaction, constraint, duress, enforcement, press, conscription, force, brute force, main force, physical force, the sword, ultima ratio, club law, lynch law, mob law, arguementum baculinum, le droit du plus fort, martial law, restraint, necessity, force majeure, Hobson's choice, compelling, coercive, coactive, inexorable,
compulsory, compulsatory, obligatory, stringent, peremptory, forcible, not to be trifled with, irresistible, compelled, fain to, by force, by force of arms, on compulsion, perforce, vi et armis, under the lash, at the point of the sword, at the point of the bayonet, forcibly, by a strong arm, under protest, in spite of one's teeth, against one's will, nolens volens, by stress of circumstances, by stress of weather, under press of, de rigueur, with a gun to one's head, I'll make him an offer he can't refuse.