Where does “সাইদ” come from?

সাইদ (Bengali) comes from Arabic سعيد, from Arabic سَعِيد.

Ancestry of “সাইদ”, step by step

Step	Language	Word	Meaning
1	Arabic	سعيد	happy, cheerful, joyous; lucky
2	Arabic	سَعِيد	—

সাইদ — Etymology, Origin & Word History | Etymology Explorer