Thir"ty (?), a. [OE. thritty, AS. �xed;ritig, �xed;rittig; akin to D. dertig, G. dreissig, Icel. �xed;rjatiu, �xed;rjatigi, �xed;rir teger, Goth. �xed;reis tigjus, i.e., three tens. See Three, and Ten, and cf. Thirteen.]
Being three times ten; consisting of one more than twenty-nine; twenty and ten; as, the month of June consists of thirty days.
© Webster 1913.
Thir"ty (?), n.; pl. Thirties ().
1.
The sum of three tens, or twenty and ten; thirty units or objects.
2.
A symbol expressing thirty, as 30, or XXX.
© Webster 1913.