thirty-oneth

From thirty-one +‎ -th (ordinal suffix).

• (UK) IPA^(key): /ˌθɜːti ˈwʌnθ/
• (US) IPA^(key): /ˌθɚti ˈwʌnθ/

thirty-oneth (not comparable)

1. (nonstandard) thirty-first

thirty-oneth (plural thirty-oneths)

1. A fractional part of which thirty-one make up a whole
   • August 15, 1896, “Brooke & Co. (Limited) v. Commissioners of Inland Revenue”, in The Weekly Reporter vol. XLIV, Supreme Court of Judicature, House of Lords, London., page 671:

     about twenty thirty-oneths in value of such sales being made as hereinafter mentioned to a syndicate of persons in the United Kingdom, about seven thirty-oneths to residents in the United States, and about four thirty-oneths to residents in other European countries and the colonies.

• thirty-first