One Piece Encyclopedia

Taisa "Captain" - Leader of the different located bases of the marines throughout all the islands from the world.
Taishou "Admiral" - The higer rank of the marines to which only the strongest ones can get. There are only three people can in this position and they are known by a color keyname, blue, red and yellow.
Taru Taiga The Taru Taiga is the raft that Usopp maded with three barrels to compete in the Donut Race.
Tenryuubito The "Tenryuubito" or "Heavenly Dragonians" are the twenty kings descendants that formed the current World Government. As such, they are therefore considered World Nobles of immense political power.
Thousand Sunny The Thousand Sunny is the second ship of the Straw Hat Pirates. It was made by Franky with the Adam's wood, the same one that was used for Gol D. Roger's Oro Jackson.
Thriller Bark The ship of Moriah's pirate crew. This is the largest ship of the word, is so big that it can be mistaken with an island.