Thirty
Thirty , adjective
[Old English thritty, Anglo-Saxon þrītig, þrittig; akin to Dutch dertig, German dreissig, Icelandic þrjātīu, þrjātigi, þrir teger, Gothic þreis tigjus, that is, three tens. See Three, and Ten, and compare Thirteen.]
Being three times ten; consisting of one more than twenty-nine; twenty and ten; as, the month of June consists of thirty days.
Thirty , noun
1.
The sum of three tens, or twenty and ten; thirty units or objects.
2.
A symbol expressing thirty, as 30, or XXX.