1 syllable:
aue, bao, blau, blauw, blough, bough, bow, brau, brough, brow, cao, cau, chao, chiao, 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, plough, 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, changdao, cheng xiao, chingtao, 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, 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, lister plough, lister plow, liuyedao, mahilyow, maranhao, miagao, middlebrow, mindanao, morgenthau, overcrow, pathet-lao, 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