1 syllable:
-clase, ace, aisse, baisse, base, bass, brace, caisse, case, cayce, chace, chase, crace, dace, drace, dspace, dtrace, face, frace, glace, grace, graisse, heyse, lace, mace, mais, nace, nspace, pace, phace, pspace, ptrace, race, rais, space, stace, stase, strace, tayce, trace, vase, wace, xbase, {brace

2 syllables:
abase, airbase, airspace, air base, altace, ambase, amesace, anelace, apace, arms race, arspace, backspace, backtrace, back brace, belace, best-case, biface, big-face, birthplace, bitbrace, blackface, black race, blank space, blueface, boat-race, boat race, boldface, bongrace, bookcase, bowgrace, braceface, braincase, briefcase, broad-base, broadbase, bucase, by-place, c-base, capcase, carcase, cardcase, car race, catface, chaincase, chalkface, cheeseface, chessbase, clayface, clearcase, clock face, clubface, coalface, codebase, coface, coinbase, couchbase, crankcase, crawlspace, crunchbase, cubase, cytase, czarface, darktrace, dbase, debase, deepface, deep space, deface, degrace, deltase, disbase, discase, disc space, disgrace, disk space, dispace, displace, display ps, dogface, dollface, doorcase, doughface, dreamspace, drivespace, e-base, efface, ekstase, embase, embrace, emplace, encase, enchase, enface, enrace, erase, espace, essbase, estrace, euclase, extase, false face, fanbase, fangface, farm-place, farmplace, findface, first base, fishbase, fly-case, footrace, foot race, forebrace, foreface, foxbase, frank-chase, free-base, freebase, fuckface, full-face, gameface, gearspace, gear case, greyface, gun case, half-space, hardcase, headcase, headspace, homebase, homeplace, horse-race, horse race, i-case, imbase, incase, inchase, ingrace, inlace, in case, itase, keybase, knee brace, koobface, laccase, lactase, laface, lambastes, landrace, landspace, laplace, last-place, lee pace, left-brace, lightface, livspace, lootcase, lovelace, mainbrace, maltase, meatspace, misplace, mixed-race, moonbase, moonface, myspace, n-space, namespace, neck brace, newspace, nodejs, non-place, noplace, null-space, nullspace, null space, nutcase, off-base, onespace, on base, outface, outpace, outplace, outrace, parcase, parcplace, pecase, pectase, percase, petase, phytase, pigface, point lace, postface, pramface, proface, rackspace, rapace, rat race, re-trace, rebase, rebrace, rechase, reed mace, relace, replace, rerebrace, retrace, right-brace, rimbase, rockface, sack race, saygrace, scapegrace, scarface, scratch race, seedcase, shoelace, shoe lace, showcase, showplace, skiptrace, ski race, skull-face, slapeface, slipcase, smallcase, smearcase, snake case, snapcase, snot-face, someplace, spore case, squarespace, staircase, stake race, starbase, steelcase, stone-face, straight face, streptase, sub-base, subbase, subspace, suitcase, sunspace, supplace, surbase, swap space, sybase, talkspace, tax base, test case, third base, thrombase, toolcase, tool case, torch race, touch base, transplace, trollface, tryptase, two-face, typecase, typeface, unbrace, uncase, unface, unlace, uptrace, vambrace, vantbrace, volte-face, warface, watchcase, watch case, webspace, wheelbase, whey-face, wheyface, white-face, whiteface, whitespace, white race, will & grace, wing case, woodface, workplace, workspace, worst-case, wry face, yacht race, {left-brace, }close-brace, }right-brace

3 syllables:
about-face, aboutface, acid-base, aerospace, aftertastes, anatase, ankle brace, annagrace, anyplace, arcaspace, army base, arobase, arrobase, aspartase, baby-face, babyface, basketcase, battlespace, blurryface, bobbin lace, boniface, bouillabaise, bouillabaisse, brazenface, breathing space, brussels lace, camelcase, case-by-case, cityplace, claiming race, clean-in-place, clinoclase, commonplace, convertase, counterbrace, country-base, coup de grace, createspace, cyberchase, cyberspace, database, david chase, demi-glace, demiglace, diabase, diastase, dioptase, dispatch case, display case, dnase, double-face, double-space, dressing case, dwelling-place, dynatrace, ecospace, eigenface, eigenspace, elastase, enclosed space, enterlace, evergrace, everspace, everyplace, face-to-face, final space, firebase, fireplace, foam-in-place, fritzl case, glasses case, gopherspace, gynobase, hackerspace, hammerspace, harness race, hatchet-face, herb-of-grace, herb of grace, hilbert space, human face, human race, hurdle race, hydratase, hydro-base, hydrospace, hyperbase, hyperspace, in-your-face, index case, innerspace, instabase, interbase, interface, interlace, interplace, interspace, invertase, in one case, isobase, jadagrace, jonbenet's, just in case, kilobase, kissy-face, knowledgebase, knowledge base, leatherface, leslie grace, letterspace, letter case, liquibase, lithoclase, living space, lower-case, lowercase, lower case, maggie grace, market-place, marketplace, megabase, mental case, metric space, monospace, nancy mace, navy base, needlecase, negroid race, notecase, oblique case, open-face, orthoclase, outer space, overgrace, packing case, paleface, panabase, paperchase, paper chase, parking space, pencil case, periclase, phosphatase, pillow-case, pillowcase, pillow lace, planetbase, poker face, polyspace, pudding-face, puddingface, quarterpace, queen anne's lace, rain-in-the-face, reductase, reed-mace, reembrace, relay race, rheobase, rocket base, roman pace, royal brace, sailing-race, sclerobase, second base, secretase, selling race, senate race, single-space, skiing race, slavic race, solvespace, state of grace, steeplechase, stoneface, stone life face, storage space, subject case, sulfatase, sulphatase, superbase, superspace, swinecase, synaptase, syntax-case, synthetase, tablespace, tallow-face, taserface, the staircase, thorough-brace, three days grace, transcriptase, translocase, triple-space, trophy case, underbrace, uniface, upper-case, uppercase, upper case, uricase, usace, welfare case, whatshisface, xpercase, year of grace, yellowface, yellow race, zero-base, {open-brace

4 syllables:
aconitase, agent-in-place, anorthoclase, antitrust case, arianespace, aromatase, as-interface, attache case, bicycle race, caucasian race, chariot race, charity case, cigarette case, custody case, cyberespace, dehydratase, duke lacrosse case, electrospace, google workspace, governor's race, graph database, indian race, in any case, isomaltase, mckenna grace, memory trace, mongoloid race, moving staircase, noomi rapace, nucleobase, objective case, obstacle race, oligoclase, operabase, overnight case, pegloticase, plagioclase, polymerase, possessive case, potato race, prisoner's base, rasburicase, reiterates, rupaul's drag race, streptokinase, tamam shud case, triphosphatase, visual space

5 syllables:
accusative case, automobile race, c3-convertase, dihydroorotase, ferrochelatase, freelance marketplace, geometric pace, grammatical case, instrumental case, interstellar space, military pace, mongolian race, open fireplace, pyrophosphatase, trespass on the case, user interface

6 syllables:
amerindian race, central park jogger case, command-line interface, command line interface, computer database, enumclaw horse sex case, four-dimensional space, fructose-bisphosphatase, garth marenghi's darkplace, lexical database, oxidoreductase, parallel interface, terri schiavo case, thefutureembrace

7 syllables:
3000 metres steeplechase, electronic database, histidinol-phosphatase, interplanetary space, o. j. simpson murder case, relational database

8 syllables:
graphical user interface, guantanamo bay naval base, unified payments interface

9 syllables:
small computer system interface

12 syllables:
musical instrument digital interface

1 syllable:
rates, skates, bates, gates, plates, states, waits, fates, straits, dates, weights, mates, eights, greats, hates, state's, states', traits, yeats

2 syllables:
awaits, cordaites, creates, debates, dictates, dire straits, gulf states, kuwait's, misstates, naucrates, relates, the fates, translates, updates

3 syllables:
desperate straits, hydrobates, hylobates

4 syllables:
united states, system of weights

5 syllables:
william butler yeats, war between the states

9 syllables:
commonwealth of independent states, capital of the united states, president of the united states

10 syllables:
constitution of the united states

11 syllables:
organization of american states

12 syllables:
attorney general of the united states