Synonyms and related words :
acute, axial, behind the scenes, capital, cardinal, causal, causative, centermost, central, centralized, centric, centroidal, centrosymmetric, charged, clamorous, climacteric, compelling, concentrated, constitutive, critical, crucial, crying, decisive, determinative, effectual, emergent, essential, etiological, exigent, focal, formative, geocentric, high-pressure, high-priority, imperative, imperious, important, insistent, instant, institutive, kairotic, key, loaded, middle, middlemost, midmost, momentous, occasional, omphalic, originative, overriding, overruling, pregnant, pressing, principal, radical, ruling, significant, umbilical, urgent, vital