Synonyms and related words :
Spartan, Spartanic, accurate, acute, astringent, attentive, austere, authoritarian, burdensome, burning, charged, choiceless, clamant, clamorous, climacteric, close, compelling, compulsory, conscientious, correct, critical, crucial, crying, decisive, delicate, demanding, detailed, dour, draining, emergent, exact, exacting, exorbitant, exquisite, extortionate, fine, finical, finicking, finicky, fussy, grasping, grievous, grim, harsh, high-pressure, high-priority, imperative, imperious, importunate, insistent, instant, kairotic, loaded, loud, mandatory, menacing, meticulous, minute, narrow, necessary, necessitous, nice, obligatory, oppressive, particular, persistent, pertinacious, pivotal, precise, precisianistic, precisionistic, pregnant, pressing, punctilious, punctual, refined, religious, rigid, rigorous, rugged, scrupulous, scrutinizing, severe, stern, strict, stringent, subtle, superincumbent, taxing, threatening, tough, unsparing, urgent, weighty, without choice