thirties n 1: the time of life between 30 and 40 [syn: {thirties}, {mid- thirties}, {thirty-something}] 2: the decade from 1930 to 1939 [syn: {thirties}, {1930s}]
Thirty \Thir"ty\, n.; pl. {Thirties}. 1. The sum of three tens, or twenty and ten; thirty units or objects. [1913 Webster] 2. A symbol expressing thirty, as 30, or XXX. [1913 Webster]