3 syllables:
technical

4 syllables:
non-technical, nontechnical, untechnical, zootechnical

5 syllables:
biotechnical, geotechnical, mnemotechnical, philotechnical, polytechnical

6 syllables:
electrotechnical

3 syllables:
tenable, equable, estival, medical, stretchable, sensual, skeletal, sextuple, pessimal, sensible, edible, meltable, vegetable, vendible, retinal, festival, aestival, flexible, spectacle, sentinel, pedestal, sepulchral, bendable, legible, credible, methanal, peccable, epochal, plentiful, sectional, seconal, decimal, vegetal, seneschal, genital, skeptical, ethical, gettable, tentacle, testable, jezebel, seminal, rentable, pennoncel, requital, spendable, chemical, pentacle, centrical, emmenthal, ethnical, helical, metical, metrical, pellicle, testicle, ventricle, vesicle

4 syllables:
impregnable, acceptable, ineffable, conventicle, dimensional, condemnable, detectable, expressible, compensable, congressional, inflectional, electable, dispensable, preventable, unquenchable, processional, injectable, digestible, adjectival, atenolol, professional, illegible, heliacal, confessional, comestible, inflexible, delectable, insensible, ascendable, defensible, trigeminal, regrettable, contemptible, defendable, correctional, extendable, untenable, amendable, centesimal, accessible, commendable, amenable, intestinal, respectable, affectional, collectible, lamentable, expendable, directional, correctable, perceptible, receptacle, contestable, execrable, recessional, polemical, incredible, conceptional, dependable, detestable, congenital, ostensible, preferable, impeccable, forgettable, collectable, compressible, susceptible, obsessional, conventional, intentional, inedible, exceptional, extensible, aesthetical, angelical, appendicle, ascendible, ascetical, calendrical, concentrical, electrical, ereshkigel, esthetical, extendible, genetical, heretical, hygienical, identical, indelible, nonsensical, obstetrical, poetical, prophetical, putrescible, symmetrical, synthetical, unethical, unmedical, unvendible

5 syllables:
hexadecimal, unexceptional, incompressible, apprehensible, comprehensible, inextensible, bidirectional, inaccessible, undependable, three-dimensional, neurochemical, indispensable, unconventional, nonprofessional, two-dimensional, unintentional, indigestible, hypothetical, inexpressible, reprehensible, irrepressible, insurrectional, indefensible, planetesimal, unforgettable, insusceptible, health professional, unacceptable, homosexual, unprofessional, algometrical, alphabetical, antithetical, archangelical, arithmetical, asymmetrical, bathymetrical, commonsensical, comprehendible, dialectical, diametrical, dietetical, ecumenical, evangelical, exegetical, geodesical, geometrical, homiletical, imperceptible, isometrical, oecumenical, parenthetical, petrochemical, theoretical, uncollectible, unsymmetrical, volumetrical

6 syllables:
omnidirectional, semiprofessional, heterosexual, recurring decimal, unidirectional, repeating decimal, multidimensional, unidimensional, paraprofessional, anemometrical, anthropometrical, antipathetical, colorimetrical, incomprehensible, infinitesimal, photoelectrical, thermoelectrical, uncomprehensible

9 syllables:
bilaterally symmetrical