mantissa

Borrowed from Latin mantissa, mantīsa, of unknown origin (said by Festus to be a loanword from Etruscan, but it may actually be from Celtic, possibly through Etruscan mediation). Coincidentally, proparoxytone Greek μάντισσα (mántissa) means "female foreteller", as in χαρτομάντισσα (chartomántissa, “cartomancer”) or χειρομάντισσα (cheiromántissa, “chiromancer”).