First Known Use: before 12th century
Dictionary
thirty
noun thir·ty \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
— 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
See thirty defined for English-language learners
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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
Other Number-Related Terms
THIRTYISH Defined for Kids
1thirty
adjective thir·ty \ˈthər-tē\
Definition of THIRTY for Kids
: being three times ten
2thirty
noun
Definition of THIRTY for Kids
: three times ten : 30
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