Mandatory rhymes with:
laudatory, predatory, accusatory, aleatory, ambulatory, anticipatory, articulatory, celebratory, circulatory, compensatory, conciliatory, confirmatory, confiscatory, congratulatory, contributory, declaratory, defamatory, depilatory, depository, deregulatory, derogatory, dilatory, discriminatory, dormitory, excretory, exculpatory, expiratory, explanatory, exploratory, hallucinatory, incantatory, inflammatory, inhibitory, interrogatory, investigatory, laboratory, laudatory, lavatory, migratory, nondiscriminatory, obligatory, observatory, oratory, oscillatory, participatory, predatory, preparatory, prohibitory, purgatory, reformatory, regulatory, repository, respiratory, retaliatory, revelatory, signatory, statutory, transitory
Mandatory sounds like:
madar, madara, madder, madeira, mader, madera, madere, madero, madora, madore, madra, madre, madry, maeder, mahathir, mahindra, mahtar, maitre, mander, manteer, manter, mantra, matador, mateer, mater, matera, mather, mathur, matra, matter, mattera, mature, maturo, mayweather, meader, meador, meander, meatier, medar, meder, mediator, medora, meeder, menter, mentor, metairie, meteor, meter, metier, metoyer, metra, metre, metro, metter, mettur, midair, midura, midyear, minder, miniature, minteer, minter, mintier, miter, mitra, mitre, mitro, moder, modrow, momentary, mondadori, mondor, mondry, monetary, monitor, monteiro, monter, monterey, montero, monterrey, montier, montroy, montuori, mother, motor, motter, moudry, moutray, muddier, mudra, mudry, munter, mutter