4 syllables:
annexionist, connectionist, defectionist, projectionist, protectionist, rejectionist, selectionist

5 syllables:
insurrectionist, introspectionist, resurrectionist, vivisectionist

7 syllables:
antivivisectionist

3 syllables:
prevalent, relevant, renascent, specialist, eloquent, negligent, heaven-sent, estimate, deficit, decadent, megabit, prejudiced, benefit, pestilent, beguilement, settlement, elegist, detriment, evident, definite, pediment, enthrallment, testament, delicate, medalist, resonant, temperament, celebrant, delegate, petulant, excellent, feculent, sentiment, element, desolate, feminist, redolent, etiquette, sediment, elegant, emigrant, registrant, elephant, recusant, benedict, eminent, excrement, methodist, regiment, curettement, tegument, exquisite, mezzotint, pessimist, tenement, geminate, hedonist, secondment, requisite, desiccant, vellicate, centralist

4 syllables:
bedevilment, inelegant, intelligent, irredentist, irrelevant, integument, impediment, embezzlement, malevolent, receptionist, prerequisite, affectionate, expressionist, geneticist, federalist, ingeminate, theosophist, maleficent, anesthetist, areca nut, new testament, nonresident, resettlement, supremacist, development, fringe benefit, executant, beneficed, presentiment, old testament, preeminent, trace element, death benefit, benevolent, white elephant, antecedent, connecticut, envelopment, sea elephant, trade deficit, eggs benedict, indefinite, secessionist, impressionist, ear specialist, heart specialist, nonresonant, predestinate, rogue elephant, self-evident, unprejudiced, saint benedict, sick benefit, tax benefit

5 syllables:
sentimentalist, antifeminist, transcendentalist, white supremacist, instrumentalist, redevelopment, underestimate, existentialist, budget deficit, fundamentalist, orientalist, picture element, frontier settlement, land development, logic element, marriage settlement, nondevelopment, rare-earth element, threshold element, unintelligent, ornamentalist, postimpressionist, sickness benefit, unaffectionate

6 syllables:
chemical element, underdevelopment, african elephant, ribbon development, housing development, federal deficit, environmentalist, fingerprint specialist, indian elephant, medical specialist, metallic element, property settlement, water development, advance death benefit

7 syllables:
identity element, arrested development, viatical settlement, alluvial sediment, imperial elephant, retirement benefit

8 syllables:
capital of connecticut, disability benefit, supplementary benefit

9 syllables:
housing and urban development

13 syllables:
department of housing and urban development

14 syllables:
secretary of housing and urban development

16 syllables:
international bank for reconstruction and development