Where does “مهاجر” come from?

مهاجر (Ottoman Turkish) comes from Arabic مُهَاجِر, from Arabic هَاجَرَ.

Ancestry of “مهاجر”, step by step

Step	Language	Word	Meaning
1	Arabic	مُهَاجِر	refugee, immigrant; emigrant
2	Arabic	هَاجَرَ	—