名詞 tt:

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
   同義詞：terrestrial time, TT, terrestrial dynamical time, TDT, ephemeris time
2. a republic in the western central Pacific Ocean in association with the United States
   同義詞：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
   同義詞：Micronesia, Federated States of Micronesia, TT