This is the 4740th most frequent Turkish word.
dert
"Trouble," "sorrow," or "problem."
In this sentence, 'dert' refers to ongoing problems or troubles that the person is experiencing.
Onun derdi hiç bitmiyor.
His trouble never ends.
Here, 'dert' is used in a more general sense to indicate 'worries' or 'concerns' that the person might have.
Dert etmene gerek yok, her şey yoluna girecek.
You don't need to worry, everything will be alright.
The phrase 'dert etme' here means 'don't make it a problem' or 'don't worry about it', highlighting a colloquial usage.