thirties noun 3adjective 1 noun[plural only]3 •The fourth decade of a century: the 1830s, 1930s, 2030s, etc.It says here on your resume that your last job was as a streetcorner apple vendor and that you haven't worked since the thirties. •The decade of one's life from age 30 through age 39.He looked to be in his thirties. •The range between 30 and 39.It's going to be in the low thirties tonight. adjective1 •From or evoking the 31st through 40th years of a century (chiefly the 1930s).Yearslong droughts? How thirties!
