Where does “اتنين” come from?

اتنين (Egyptian Arabic) comes from Arabic اثنان, from Arabic اِثْنَان — two.

اتنين (Egyptian Arabic): two

Definitions

Step	Language	Word	Meaning
1	Arabic	اثنان	two
2	Arabic	اِثْنَان	two

اتنين — Etymology, Origin & Word History | Etymology Explorer