- next after the twenty-ninth; being the ordinal number for 30.
- being one of 30 equal parts.
- a thirtieth part, especially of one (1/30).
- the thirtieth member of a series.
Origin of thirtieth
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for thirtieth
By the thirtieth time it has become a word like "snark" or "pobble."Alarms and Discursions
G. K. Chesterton
She was one of those blondes who fade rapidly after their thirtieth year.Fruitfulness
And now if ye will do battle, come again on the thirtieth day from hence.Cyropaedia
"In the Thirtieth street station-house, sir," she briefly responded.The Masked Bridal
Mrs. Georgie Sheldon
The Army of the Valley had its orders from Strasburg the night of the thirtieth.The Long Roll
- (usually prenominal)
- being the ordinal number of thirty in counting order, position, time, etc: often written 30th
- (as noun)the thirtieth of the month
- one of 30 approximately equal parts of something
- (as modifier)a thirtieth part
- the fraction equal to one divided by 30 (1/30)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for thirtieth
Online Etymology Dictionary, © 2010 Douglas Harper