DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   TT
       n 1: (astronomy) a measure of time defined by Earth's orbital
            motion; terrestrial time is mean solar time corrected for
            the irregularities of the Earth's motions [syn:
            terrestrial time, TT, terrestrial dynamical time,
            TDT, ephemeris time]
       2: a republic in the western central Pacific Ocean in
          association with the United States [syn: Palau, Republic
    of Palau, TT]
       3: a country scattered over Micronesia with a constitutional
          government in free association with the United States;
          achieved independence in 1986 [syn: Micronesia, Federated
    States of Micronesia, TT]