This is the 783rd most frequent Arabic word.
تصبح
"تصبح" means "to become" or "to turn into."
Here, 'تصبح' means 'becomes', indicating a change of state.
تصبح السماء زرقاء بعد الشروق.
The sky becomes blue after sunrise.
In this sentence, 'تصبح' is part of the phrase 'تصبح على خير' used as a way to wish someone a good night.
تصبح على خير.
Goodnight.
Here, 'تصبح' means 'become', indicating a potential change or future state.