1. (

• terrestrial_time ,
• TT ,
• terrestrial_dynamical_time ,
• TDT ,
• ephemeris_time

) (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 ;

2. (

• Palau ,
• Republic_of_Palau ,
• TT ,

) a republic in the western central Pacific Ocean in association with the United States ;

3. (

• Micronesia ,
• Federated_States_of_Micronesia ,
• TT

) a country scattered over Micronesia with a constitutional government in free association with the United States; achieved independence in 1986 ;