1 syllable:
'course, borse, bourse, coarse, corse, course, dorce, dorse, force, forse, fource, fourths, four ps, g-force, gorce, gorse, hoarse, horse, korce, morse, morss, nforce, norse, nourse, porse, scorce, scourse, sorce, sore ss, source, torse, vorce, zorse

2 syllables:
a-force, afforce, ahorse, amorce, antrorse, bawhorse, broforce, bruteforce, cart horse, catorce, change course, closed-source, clotheshorse, coach horse, cock-horse, cockhorse, commorse, concourse, crowdsource, dark-horse, darkforce, darkhorse, dark horse, dawn horse, deadhorse, deforce, dextrorse, dishorse, divorce, downforce, draft horse, draught horse, drayhorse, dray horse, dustforce, ecorse, efforce, endorse, enforce, ensource, entorse, extrorse, farm horse, finnhorse, firstsource, geforce, gencorp's, gift-horse, gift horse, golf course, gunforce, haute-corse, healthsource, hog-morse, indorse, insource, introrse, in force, jump force, laforce, lifeforce, light source, long horse, main course, male horse, midcourse, nisource, of course, old norse, one-horse, outsource, packhorse, parforce, partsource, perforce, plow horse, point source, pole horse, post-horse, post horse, pound-force, praemorse, premorse, q-force, race-horse, racehorse, race horse, ranforce, rayforce, rear-horse, reardorse, redhorse, remorse, ressource, retrorse, salesforce, sales force, sawhorse, seahorse, sea horse, shire horse, side horse, spellforce, stick horse, stone-horse, strong force, stud-horse, studhorse, taskforce, task force, telsource, tigsource, triforce, unhorse, war-horse, weak force, wheel-horse, wheel horse, whitehorse, white horse, wild horse, workforce, workhorse, work force, x-force

3 syllables:
agresource, change of course, charley-horse, charleyhorse, color force, counterforce, crazyhorse, cybersource, danger force, datasource, dragonforce, driving force, dunsterforce, fairbanks-morse, female horse, field of force, fireforce, fire force, flying horse, geo-force, harness horse, hobby-horse, intercourse, in due course, ironsource, iron horse, labor force, line of force, megaforce, moral force, open-source, outercourse, overforce, parcelforce, police force, pommel horse, proto-norse, quarterhorse, quarter horse, re-enforce, reenforce, reinforce, riding horse, river horse, rocking-horse, rocking horse, saddle horse, sinistrorse, sparklehorse, stalking-horse, teleforce, tour de force, towel horse, trojan horse, trotting horse, ultraforce, uniforce, unisource, vaulting horse, vital force, walking horse, watercourse, waterhorse, wikisource, wilberforce, with full force, wooden horse

4 syllables:
afghan air force, attractive force, cavalry horse, extension course, german air force, have intercourse, kilogram-force, magnetic force, man-on-a-horse, matter of course, radio source, refresher course, repulsive force, retarding force, royal air force, russian air force

5 syllables:
anal intercourse, centrifugal force, correspondence course, hellenic air force, indian air force, israeli air force, military force, pakistan air force, philippine air force, security force, social intercourse

6 syllables:
aqua teen hunger force, australian defence force, gravitational force, magnetic line of force, orientation course, plantation walking horse, reconnaissance in force, sexual intercourse, tennessee walking horse, ultraviolet source, united states space force

7 syllables:
american saddle horse, electrical line of force, japan air self-defense force, massive open online course, private security force, royal australian air force

8 syllables:
royal canadian air force

3 syllables:
caudine forks