- a cardinal number, 10 times 3.
- a symbol for this number, as 30 or XXX.
- a set of this many persons or things.
- 30-dash.
- 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.
- amounting to 30 in number.
- the cardinal number that is the product of ten and three
- a numeral, 30, XXX, etc, representing this number
- the numbers 30–39, esp the 30th to the 39th year of a person's life or of a century
- the amount or quantity that is three times as big as ten
- something representing, represented by, or consisting of 30 units
- amounting to thirty
- (as pronoun)
