This is the 4806th most frequent Turkish word.
dönme
"Conversion" or "return," often referring to turning back, rotating, or, historically, a converted person.
In this sentence, 'dönme' is an imperative negative form of the verb 'dönmek,' used to instruct someone not to turn at a direction.
Yolun sonunda sağa dönme.
At the end of the road, don't turn right.
Here, 'dönmeden' is a derivation of 'dönmek,' meaning 'before turning or returning,' showing use in temporal conditions.
Annesinin yanına dönmeden önce ona haber verdi.
Before returning to his mother, he informed her.
In this context, 'dönmeye' is the infinitive form of 'dönmek,' indicating that an action of spinning or rotating is initiated.