n. the time of life between 30 and 40.
n. pl. A name given to three several issues of United States Treasury notes, made during the Civil War, in denominations of $50 and over, bearing interest at the rate of seven and three tenths (thirty hundredths) per cent annually. Within a few years they were all redeemed or funded. [ 1913 Webster ]
a. [ From Thirty: cf. AS. þrītigōða. ]
n. The quotient of a unit divided by thirty; one of thirty equal parts. [ 1913 Webster ]