I found this on the net. I do not know whether it adds anything to the discussion. Thanks.

"Tadbhav words come from Sanskrit but through some regional language like Pali or Prakrit. They have changed along the way. Examples are bhai, behan, naak and kaan. Deshaj words come from languages other than Sanskrit, e.g. garhbarh and jagmag. Videshi words are words taken from foreign languages like Arabic, Persian, French and English. For instance, allah, namaz, kameez, aspataal and rail."