tatsama

Learned borrowing from Sanskrit तत्सम (tatsama). Tatsama was originally employed to refer to those inherited Prakrit words that were identical in form with Sanskrit; later it came to refer to learned loans introduced into the post-Prakritic speech as well. Traditionally, the term was used for both inherited words that were unmodified in form, and learned words. However from a strict linguistic point of view, the term refers only to learned borrowings from Sanskrit.

来源：wiktionary