thirty

thir·ty

noun \ˈthər-tē\

: the number 30

thirties : the numbers ranging from 30 to 39

: a set of years ending in digits ranging from 30 to 39

plural thirties

Full Definition of THIRTY

1

:  a number equal to three times 10 — see number table

2

plural :  the numbers 30 to 39; specifically :  the years 30 to 39 in a lifetime or century

3

:  a sign of completion :  end —usually written 30 <wrote thirty on the last page of the story>

4

:  the second point scored by a side in a game of tennis

— thir·ti·eth \-tē-əth\ adjective or noun

— thirty adjective

— thirty pronoun, plural in construction

— thir·ty·ish \-ish\ adjective

Examples of THIRTY

1. The temperature outside is in the high thirties.
2. He is in his thirties.

Origin of THIRTY

Middle English thritty, from thritty, adjective, from Old English thrītig, from thrītig group of 30, from thrīe three + -tig group of ten; akin to Old English tīen ten

First Known Use: before 12th century

Other Number-Related Terms

jubilee, myriad, quarantine, score, twain

Rhymes with THIRTY

dirty, flirty, QWERTY, shirty