TPTK is the shortcut for "Top Pair Top Kicker". In French, we could talk about "best pair with best sidekick". For example, if you have AK on 2-5-K-7-7, you have TPTK with the pair of kings "kicked" to the ace. The expression TPTK is rather used on the discussion forums. You will see it in writing, but it is very rare that you will hear someone say they have TPTK. You may also read about it in some poker strategy books.
TPTK, TPFK, TPBK
We took the example above of AK on 2-5-K-7-7. The highest pair with the best sidekick is defined as TPTK. If we had KJ on the same board, we would have qualified our hand as TPFK, i.e., Top Pair Fair Kicker (best pair with a good sidekick). A hand like K6 on the same board (2-5-K-7-7) would instead have been defined as TPBK, i.e., Top Paire Bad Kicker (best pair with weak sidekick). Generally, when you are only two after the flop, TPTK will be a very strong hand (unless you had a lot of resistance from your opponent).