There are a total of 124 9-letter words containing 'nth', and the number may vary in different dictionaries. You can specify the dictionary and order.

• absinthes ₁₅
• ailanthus ₁₄
• amaranths ₁₅
• amianthus ₁₆
• anthelion ₁₄
• antheming ₁₈
• anthemion ₁₆
• antherids ₁₃
• anthocyan ₁₈
• anthodium ₁₇
• anthology ₁₇
• anthozoan ₂₂
• anthraces ₁₅
• anthropic ₁₈
• anthurium ₁₇
• aunthoods ₁₄
• benthonic ₁₉
• benthoses ₁₅
• billionth ₁₇
• bimonthly ₂₁
• cantharis ₁₅
• cantharus ₁₆
• chrysanth ₁₉
• clianthus ₁₇
• colocynth ₂₁
• danthonia ₁₄
• downthrew ₁₉
• downthrow ₁₉
• elevenths ₁₇
• enanthema ₁₆
• enthralls ₁₄
• enthroned ₁₄
• enthrones ₁₃
• enthusing ₁₆
• enthymeme ₂₀
• exanthema ₂₂
• exanthems ₂₂
• fenthions ₁₆
• fifteenth ₁₈
• helminths ₁₈
• hyacinths ₁₉
• hydranths ₁₇
• hypanthia ₁₉
• inthralls ₁₄
• inthroned ₁₄
• inthrones ₁₃
• jacinthes ₂₄
• labyrinth ₁₈
• lanthanum ₁₈
• lanthorns ₁₄
• loranthus ₁₄
• menthenes ₁₆
• midmonths ₁₉
• millionth ₁₇
• monthlies ₁₆
• monthlong ₁₉
• nepenthes ₁₆
• nontheism ₁₆
• nontheist ₁₃
• pantheism ₁₈
• pantheist ₁₅
• pantheons ₁₆
• penthouse ₁₆
• perianths ₁₅
• polyantha ₁₈
• polyanthi ₁₈
• printhead ₁₆
• sainthood ₁₃
• seventhly ₁₉
• sixteenth ₁₉
• synthases ₁₄
• syntheses ₁₄
• synthesis ₁₄
• synthetic ₁₇
• terebinth ₁₅
• umpteenth ₁₉
• unthanked ₁₉
• unthawing ₁₉
• unthought ₁₈
• unthreads ₁₄
• unthrifty ₁₈
• unthroned ₁₅
• unthrones ₁₄
• xanthates ₁₉
• xantheins ₂₀
• xanthenes ₂₀
• xanthines ₂₀
• xanthomas ₂₂
• xanthones ₂₀
• zillionth ₂₃
• acanthine ₁₄
• acanthoid ₁₅
• acanthous ₁₄
• ailanthic ₁₄
• anthozoic ₂₃
• anthraxes ₁₉
• canthitis ₁₄
• epicanthi ₁₆
• flinthead ₁₆
• jillionth ₁₉
• lanthanon ₁₂
• synthpops ₁₉
• acanthins ₁₄
• ananthous ₁₂
• anthocarp ₁₆
• anthotaxy ₂₂
• anthracic ₁₆
• blunthead ₁₅
• calanthes ₁₄
• cantharid ₁₅
• canthooks ₁₈
• encanthis ₁₄
• gianthood ₁₄
• monthling ₁₅
• oenanthic ₁₄
• panthenol ₁₄
• pyracanth ₁₉
• synanthic ₁₇
• synthroni ₁₅
• unthrifts ₁₅
• wanthills ₁₅
• xanthisms ₂₁
• xanthoxyl ₂₉
• zanthoxyl ₃₁

There are 124 9-letter words containing nth in the well-known word game dictionary, 94 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 119 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 90 in the Words with Friends (WWF) dictionary.