thirty-first

[ thur-tee-furst ]
/ ˈθɜr tiˈfɜrst /

adjective

next after the thirtieth; being the ordinal number for 31.
being one of 31 equal parts.

noun

a thirty-first part, especially of one (1/31).
the thirty-first member of a series.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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