TT

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}]

from The Free On-line Dictionary of Computing (8 July 2008)

tt

   <networking> The {country code} for Trinidad and Tobago.

   (1999-01-27)