The cardinal number occurring after twenty-nine and before thirty-one, represented in Arabic numerals as 30.

(slang) A rack of thirty beers.

plural of thirty-thirty

(firearms) A thirty calibre firearm designed for cartridges that originally held thirty grains of smokeless powder.

plural of thirty

A decade starting with the year xx30, most usually the decade from 1930 to 1939. / The decade of one's life from age 30 through age 39. / (temperature, rates) The range between 30 and 39.

From or evoking the 31st through 40th years of a century (chiefly the 1930s).

Obsolete spelling of thirty

The cardinal number immediately following thirty and before thirty-two; thirty plus one.

The cardinal number immediately following thirty-seven and preceding thirty-nine.