Tubby, which means fat
Tourist
The word is "currant."
treat
If it were someone specifically from the island of Tahiti then the answer is Tahitian.
"Tiger" is a two-syllable word that starts with a T.
The word you're looking for is "teapot." It starts with a T, has another T in the middle, and ends with a T. So, there you have it, a word with T at the beginning, T inside, and T at the end. Now go impress someone with that fun fact!
tilt
tycoon
Teapot
A seven letter word that starts with D and ends with T: decrypt
An eight letter word that starts with S and ends with T: satiristshortestsmallestsmarteststagnantstalwartstiffeststridentsubtract
The word bat starts with the latter b and it ends with the latter a and t