thirty

[thur-tee]

noun

plural

thirties 

1. a cardinal number, 10 times 3.

2. a symbol for this number, as 30 or XXX.

3. a set of this many persons or things.

4. Printing, Journalism.,  30-dash.

5. thirties, the numbers, years, degrees, or the like, from 30 through 39, as in referring to numbered streets, indicating the years of a lifetime or of a century, or referring to degrees of temperature.

   He works in the East Thirties. She must be in her thirties. The temperature was in the thirties yesterday.

adjective

1. amounting to 30 in number.

thirty

/ ˈθɜːtɪ /

noun

1. the cardinal number that is the product of ten and three See also number

2. a numeral, 30, XXX, etc, representing this number

3. (plural) the numbers 30–39, esp the 30th to the 39th year of a person's life or of a century

4. the amount or quantity that is three times as big as ten

5. something representing, represented by, or consisting of 30 units

determiner

1. 1. amounting to thirty

      thirty trees

   2. ( as pronoun )

      thirty are broken

Word History and Origins

Origin of thirty¹

before 900; Middle English thritty, Old English thrītig, equivalent to thrī three + -tig -ty ¹; cognate with Dutch dertig, German dreissig, Old Norse thrjātīu

Word History and Origins

Origin of thirty¹

Old English thrītig; see _three , _-ty ¹

Example Sentences

Using oVert datasets, the team examined CT scans from more than thirty lizards and snakes, including three chameleon species representing major lineages.

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I called countless times over that next week and must’ve left about thirty voicemails.

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It was six thirty exactly, time for the speeches to begin.

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“Ten . . . twenty . . . thirty . . .” The children were excellent counters, which merely underscored how very many pieces of correspondence were already on hand.

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It was early—barely seven thirty in the morning—so the place was practically empty.

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When To Use

Spelling tips for 30

The word thirty (30) is hard to spell because it doesn’t simply combine the spelling of the base number (three) with the suffix -ty, as is done in other easy-to-remember spellings like sixty and seventy.  How to spell thirty: When three is combined with suffixes, it transforms from three (a cardinal number) to third (an ordinal number).Then, the d is dropped: thirteen (not thirdteen); thirty (not thirdty). Remember: there's no d in thirty.