There are a total of 17 9-letter words containing 'ao', and the number may vary in different dictionaries. You can specify the dictionary and order.

• bresaolas ₁₃
• gaolbirds ₁₆
• gaolbreak ₁₉
• gaolhouse ₁₅
• gheraoing ₁₆
• kaoliangs ₁₇
• kaolinise ₁₅
• kaolinite ₁₅
• kaolinize ₂₄
• logaoedic ₁₆
• pharaonic ₁₈
• engaoling ₁₁
• gaoleress ₁₀
• laodicean ₁₂
• ongaongas ₁₁
• qinghaosu ₂₂
• taoiseach ₁₄

There are 17 9-letter words containing ao in the well-known word game dictionary, 8 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 15 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 11 in the Words with Friends (WWF) dictionary.