3 syllables:
principal, principle

4 syllables:
first principle, in principle, life principle, school principal, subprincipal, unprinciple, vice-principal

5 syllables:
basic principle, bitter principle, legal principle, moral principle, pleasure principle, vital principle, working principle

6 syllables:
bernoulli's principle, exclusion principle, judicial principle

7 syllables:
fundamental principle, reality principle, uncertainty principle, victoria principal

8 syllables:
pauli exclusion principle

3 syllables:
bristletail, chippendale, tripletail, biblical, biddable, bindable, binnacle, bridgeable, clinical, criminal, cystocele, digital, drinkable, fictional, finagle, finical, fixable, imbecile, integral, livable, liveable, minimal, miscible, miserable, mixable, mythical, pinnacle, pitiful, pivotal, printable, quizzical, risible, shrinkable, silicle, sinkable, syllable, synchronal, thimbleful, thinkable, tillable, trigonal, typical, vincible, visible, visual

4 syllables:
additional, admissible, admittable, admittible, antipodal, conditional, convincible, despicable, dissyllable, disyllable, divisible, divisional, duplicable, episcopal, equivocal, explicable, extricable, forgivable, formidable, hospitable, immiscible, indictable, invincible, invisible, medicinal, municipal, nonfictional, nutritional, original, papistical, permissible, political, pontifical, predictable, provisional, reciprocal, rescindable, resistible, sophistical, traditional, transitional, transmissible, transmittable, trisyllable, unclimbable, undrinkable, unlivable, unliveable, unmixable, unprintable, unshrinkable, unsinkable, unthinkable, war criminal

5 syllables:
aboriginal, apparitional, appositional, archepiscopal, archiepiscopal, decasyllable, desperate criminal, diacritical, inadmissible, individual, inexplicable, inhospitable, irresistible, monosyllable, nonmedicinal, nonreciprocal, nontraditional, nontransmissible, octosyllable, suppositional, unassignable, unconditional, unequivocal, unforgivable, unmedicinal, unoriginal, unpredictable, untraditional

6 syllables:
coenobitical, definite integral

7 syllables:
habitual criminal, indefinite integral