1 syllable:
aue, bao, blau, blauw, blough, bough, bow, brau, brough, brow, cao, cau, chao, chiao, chow, ciao, clough, cow, crough, dao, daopao, dow, dowe, drough, fao, frau, gnau, gow, grau, graue, hao, hau, hmpao, how, howe, hsiao, jwoww, kao, kau, klaue, kough, lao, lau, lmmfao, lough, mao, now, pao, pfau, plow, pough, pow, powe, prough, prow, rao, rau, sao, schlau, schlough, schow, scow, shao, shough, shrow, skow, sough, sow, sprow, strau, strough, tao, thao, thau, thou, tpe wau, tsao, vdpau, vow, wow, xiao, yao, yow, zhao, zschau

2 syllables:
aarau, al-fao, allow, and how, ant cow, arau, aschgrau, avow, bacau, bandow, bilbao, bow-wow, bowwow, brandow, breastplough, cabiao, cacau, cahow, carwow, cash cow, cat chow, changdao, cheng xiao, chingtao, chow chow, cibao, cocao, dadao, depauw, dessau, devow, endow, eyebrow, feldgrau, fernao, filyaw, first cow, foclmao, fuyao, guandao, hausfrau, highbrow, hofbrau, i-thou, jarchow, jungfrau, just now, kapow, know-how, kowtow, kuntao, lanao, landau, latiao, lessnau, liao, lichtblau, ling-pao, locao, luau, lubao, macao, macau, maicao, mandaue, maomao, margao, mcdow, mcgough, meow, miaodao, mike howe, milch cow, milk cow, monschau, mouth bow, nandao, nanzhao, ndau, neelghau, nylghau, ogowe, outbow, pathao, pegao, pingyao, podao, pow-wow, powwow, pudao, purewow, qiao, qingdao, qipao, right now, rizhao, roflmao, rotflmao, rotglmao, sadao, safflow, sea cow, serowe, sestao, shen-pao, shimao, shitao, shou-lao, simao, snowplough, snowplow, somehow, sorkow, sound bow, speak now, taobao, tian tao, tien-pao, til now, todd-ao, tsingtao, tumbao, turnbough, unbow, unnao, warehou, wodao, wow-wow, xinyao, yarbough, youdao

3 syllables:
ahegao, amy chow, andrew howe, anyhow, apayao, atyrau, bajaao, barbakow, bella ciao, cabuyao, cacajao, cainiao, carabao, cedeao, changpeng zhao, conceicao, curaao, curacao, dairy cow, dazibao, disallow, disavow, disavow', ehefrau, eigengrau, geforce now, gong lijiao, goodenough, guilinggao, here and now, he bingjiao, hongyipao, huang zitao, huludao, humacao, ifugao, initao, jiandao, kabeljauw, krakatao, liang chow, lister plow, liuyedao, mahilyow, maranhao, miagao, middlebrow, mindanao, morgenthau, overcrow, pathet-lao, puppy chow, qinhuangdao, recurve bow, rowdydow, sacred cow, schering-plough, shaohao, shi tingmao, sillyhow, siopao, springing cow, take a bow, tamarao, tongliao, toutiao, until now, up to now, wikihow, xiantiandao, xiaolongbao, yanmaodao, yaorenmao, yiguandao, youtiao, zhanmadao, zhenniao

4 syllables:
anhalt-dessau, charlotte nicdao, john allen chau, kitaotao, lmfao, maguindanao, manny pacquiao, marianao, martin landau, maschinenbau, violin bow

5 syllables:
athletic bilbao, caniapiscau, coco de macao, holier-than-thou

6 syllables:
henry david thoreau