1 syllable:
acts, ax, axe, backes, backs, bax, black's, blacks, blacks', blacs, bracks, cac's, caq's, clacks, claques, cracks, daccs, dacks, dacs, dax, dax', dracs, dtracs, facce, fax, flachs, flacks, flaks, flax, fracs, hacks, haq's, jack's, jacks, jacques', jaques, knacks, lac's, lachs, lacks, lakhs, lax, mac's, mack's, macks, macs, max, maxx, nste acs, ntacs, pac's, packs, pacs, pacts, pakse, pax, plack's, plaques, plax, quacks, racks, rax, saccs, sachs, sachs', sacks, sacques, sacs, saks, sax, saxe, shacks, slacks, slaxx, smacks, snacks, spacs, stac's, stacks, stacs, tachs, tacks, tax, track's, tracks, trax, traxx, vax, wacks, whacks, wracks, yacks, yax, zack's, zacks, zzzax

2 syllables:
addax, aipac's, ajax, amtrak's, anzacs, attacks, audax, awacs, backpacks, backtracks, banjax, bataks, baumax, baymax, bees-wax, beeswax, blackjacks, blendax, bluestacks, bootblacks, bootjacks, borax, brasstracks, break-axe, breakax, breakaxe, britax, broad-axe, broadax, broadaxe, bushwhacks, buybacks, callbacks, carfax, carjacks, ceefax, chaffwax, cheapjacks, chillax, chirac's, climax, cognacs, colfax, comebacks, compaq's, contacts, contax, coolmax, corax, cutbacks, death tax, dewax, dimacs, drawbacks, earwax, eastpac's, emacs, ex-lax, fairfax, fairtax, fallax, fallbacks, fastbacks, fastracks, filmax, finbacks, flapjacks, flashbacks, flomax, fullbacks, galax, gift tax, gimcracks, givebacks, goobacks, gopac's, gravlax, greenback's, greenbacks, half-tracks, halfbacks, hapax, hardbacks, hardtacks, harpax, hatchbacks, haystacks, hdtracks, hijacks, hogbacks, holdbacks, humpbacks, hunchbacks, ice ax, ice axe, imacs, imax, imax', impacts, instax, intacs, ipecacs, joymax, kgbvax, kickbacks, kipchaks, klymaxx, knapsacks, knick-knacks, knickknacks, kodak's, koufax, kremvax, krymchaks, land tax, leasebacks, lilacs, limax, lomax, lorax, madlax, malax, mandrax, mastax, mathjax, mcvax, meataxe, mendax, midpac's, mossbacks, muntjacs, mytracks, newsmax, opax, packsacks, packwax, panchax, parmacs, paxwax, paybacks, pentax, picaxe, pickax, pickaxe, pimax, playbacks, poll-tax, pollax, pollaxe, poll tax, pre-tax, pretax, pullbacks, q-max, qmax, racetracks, ransacks, re/max, redbacks, relax, repacks, ridgebacks, rollbacks, rotax, rothwax, rucksacks, sales tax, sam & max, schweinshaxe, seatbacks, setbacks, shellacs, shoeblacks, showmax, sidetracks, skewbacks, skipjack's, skipjacks, skyjacks, slingbacks, smilax, smokestacks, snorlax, snowpacks, soulwax, soundtracks, spacemacs, spalax, spantax, stamp tax, storax, supplejacks, surtax, switchbacks, syntax, tailbacks, tampax, tarmacs, tay-sachs, tecdax, terrax, thermax, throwbacks, thumbtacks, tiebacks, toad-flax, toadflax, trossachs, ty-sachs, unlax, unpacks, vivax, wattstax, wefax, westpac's, wi-max, wimax, wisecracks, wood-wax, xemacs, zwiebacks

3 syllables:
afc ajax, affymax, aframax, after-tax, aftertax, almanacks, almanacs, amberjacks, animax, anoraks, antitax, applejacks, armagnacs, atarax, audimax, ava max, bangavax, battle-ax, battle-axe, bithorax, blasterjaxx, bosniacs, brainiacs, cadillac's, cadillacs, canvasbacks, carapax, cardiacs, celiacs, cluniacs, common ax, common axe, corbevax, cornerbacks, crackerjacks, cul-de-sacs, dagger-axe, dayton ax, dayton axe, devil's flax, diamondbacks, direct tax, disclimax, ecotax, edimax, equifax, erymax, estate tax, excise tax, filofax, fireman's ax, fireman's axe, florafax, fosamax, franchise tax, garrulax, give the axe, glycine max, gonyaulax, gravadlax, gunnysacks, halifax, handymax, haversacks, hidden tax, iatacs, income tax, interfax, leatherbacks, license tax, lumberjacks, macintax, maniacs, mbalax, microvax, minimax, miramax, mullenax, natterjacks, neoax, novavax, numberjacks, officemax, omnifax, omnimax, openstax, osedax, overtax, overwax, paperbacks, parallax, petromax, piggybacks, pontiac's, pontiacs, pricklebacks, quarterbacks, razorback's, razorbacks, sassenachs, scolopax, scramasax, sealing-wax, seawaymax, shadowfax, silverbacks, single tax, stack-o-tracks, steeplejacks, sticklebacks, subclimax, suezmax, supermac's, supermax, supertax, sycorax, telefax, terramax, thoroughwax, totonacs, transfer tax, trichoplax, turbotax, uemacs, vasomax, weatherwax, western ax, western axe, wolenzac's, xtacacs, zithromax, zodiacs

4 syllables:
737-max, amnesiacs, anticlimax, byrdmaniax, chylothorax, coeliacs, counter-attacks, counterattacks, demoniacs, elegiacs, endolimax, entothorax, fitgirl repacks, gasoline tax, genethliacs, genus galax, haemothorax, hbo max, hemithorax, hemoothorax, hemothorax, hylophylax, indirect tax, insomniacs, mesothorax, metasyntax, metathorax, microemacs, micrognuemacs, morphosyntax, myeloplax, navitoclax, nycticorax, paranoiacs, parodontax, plectrophenax, pneumothorax, progressive tax, property tax, pyothorax, pyrrhocorax, radiofax, simoniacs, squalicorax, stenothorax, stepmaniax, venetoclax, withholding tax

5 syllables:
802.11ax, animaniacs, boeing 737 max, capital gains tax, caterpillar tracks, cephalothorax, dipsomaniacs, egomaniacs, estimated tax, haematothorax, hemophiliacs, henrietta lacks, hermann maurice saxe, inheritance tax, kleptomaniacs, monomaniacs, nymphomaniacs, phalacrocorax, plagioclimax, pneumatothorax, pyopneumothorax, pyromaniacs, sexual climax, stellar parallax, value-added tax, vvo2max

6 syllables:
2011 norway attacks, annual parallax, d.c. sniper attacks, diurnal parallax, expectiminimax, haemopneumothorax, hemopneumothorax, hydropneumothorax, megalomaniacs, pneumohemothorax, pneumopyothorax, pyohemothorax

7 syllables:
2008 mumbai attacks, geocentric parallax, horizontal parallax, last tango in halifax

8 syllables:
september 11 attacks

10 syllables:
declaration of estimated tax

11 syllables:
november 2015 paris attacks

1 syllable:
wraps, taps, maps, scraps, lapse, gaps, traps, facts, caps, flaps, craps, schnapps, capps, schnaps, straps

2 syllables:
elapse, collapse, perhaps, contracts, relapse, attracts, prolapse, reacts, shoot craps

3 syllables:
book of facts, book of maps, pezophaps

4 syllables:
aspidelaps, dendrocolaptes, rhynchoelaps

7 syllables:
creating by mental acts