资料来源 : pyDict

三十,3030年代;30岁,30到39岁的时期

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Thirty \Thir"ty\, a. [OE. thritty, AS. [thorn]r[=i]tig,
   [thorn]rittig; akin to D. dertig, G. dreissig, Icel.
   [thorn]rj[=a]t[=i]u, [thorn]rj[=a]tigi, [thorn]rir teger,
   Goth. [thorn]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.

Thirty \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.

资料来源 : WordNet®

thirty
     adj : being ten more than twenty [syn: {30}, {xxx}]

thirty
     n : the cardinal number that is the product of ten and three
         [syn: {30}, {XXX}]