There are a total of 20 9-letter words containing 'lays', and the number may vary in different dictionaries. You can specify the dictionary and order.

• downplays ₂₀
• fireclays ₁₈
• foreplays ₁₈
• interlays ₁₃
• layshafts ₁₇
• overplays ₁₉
• pipeclays ₂₁
• playsuits ₁₆
• pureplays ₁₉
• roleplays ₁₆
• teleplays ₁₆
• underlays ₁₅
• wordplays ₁₉
• claystone ₁₄
• gameplays ₁₇
• ballclays ₁₆
• bangalays ₁₅
• gondelays ₁₄
• handplays ₁₈
• laystalls ₁₂

There are 20 9-letter words containing lays in the well-known word game dictionary, 12 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 18 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 13 in the Words with Friends (WWF) dictionary.