sixties

from WordNet (r) 3.0 (2006)

sixties
    n 1: the decade from 1960 to 1969 [syn: {sixties}, {1960s}]
    2: the time of life between 60 and 70 [syn: {sixties}, {mid-
       sixties}]

from The Collaborative International Dictionary of English v.0.48

Sixty \Six"ty\, n.; pl. {Sixties}.
   1. The sum of six times ten; sixty units or objects.
      [1913 Webster]

   2. A symbol representing sixty units, as 60, lx., or LX.
      [1913 Webster]