2 syllables:
bed-wetter, behter, better, bettor, debtor, detter, detur, etter, fetter, fretter, geter, getter, get her, guetter, heter, heter-, jetter, jetur, ketter, letter, let her, metter, mettere, mettre, mettur, met her, netter, petar, petr, petre, petter, retter, rhetor, schetter, setter, set her, shetter, stetter, sweater, tetter, tretter, tschetter, veter, vetere, vetter, wetter, whetter, yetter, yet her

3 syllables:
abetter, abettor, air letter, barretor, barretter, bedwetter, begetter, besetter, black-letter, blackletter, black letter, block letter, bloodletter, boatsetter, bonesetter, chain letter, codebtor, commettre, crank letter, dead letter, embetter, enfetter, filmsetter, forgetter, forget her, form letter, four-letter, fumetere, gill-netter, gillnetter, go-getter, had better, insetter, jet-setter, kris tschetter, linkletter, love letter, news-letter, night letter, pace-setter, pacesetter, permettre, pinsetter, pipetter, pipettor, projeter, red-letter, red setter, regretter, resetter, rivetter, roughsetter, short letter, small letter, softletter, soumettre, sujetar, touretter, transmettre, trend-setter, trendsetter, typesetter, unfetter, upsetter, upset her, usenetter, vignetter, vote-getter, wadsetter, wage setter, wohlstetter

4 syllables:
airmail letter, assujettir, business letter, carburetter, carburettor, english setter, gordon setter, imagesetter, irish setter, market letter, open letter, photosetter, rosentreter, scarlet letter, stellvertreter, to the letter, underletter, undersetter

5 syllables:
investment letter, personal letter, phototypesetter, teletypesetter, varsity letter

6 syllables:
encyclical letter, polyphonic letter

7 syllables:
h.a.m.m.e.r.

3 syllables:
bootlegger