I. ˈthər]d.]ēə̇th, ˈthə̄], ˈthəi], ]t], ]iə̇th\ adjective
Etymology: Middle English thrittithe, from Old English thrītigotha (akin to Old Norse thrītugandi ), from thrītig thirty + -otha, -tha -th
1. : being number 30 in a countable series
the thirtieth day
— see number table
2. : being one of 30 equal parts into which anything is divisible
a thirtieth share of the money
II. noun
( -s )
1. : number 30 in a countable series
the thirtieth of the month
2. : the quotient of a unit divided by 30 : one of 30 equal parts of anything
one thirtieth of the total