-trix
suffix, ending of Latin feminine agent-nouns (with stems in -trīc-, acc. -tricem, whence Fr. -trice: see -trice), corresponding to masculines in -tor, as adjūtrix female helper, bellātrix female warrior, imperātrix female commander, empress, inventrix female discoverer, vēnātrix huntress, etc.; sometimes used adjectively, as victrix victorious, ultrix avenging. Several of these nouns were adopted in Eng., from ancient or mediæval Latin, in the 15th c. and later, as administratrix, consolatrix, creatrix, executrix, mediatrix, persecutrix, testatrix, etc.; and others formed on the analogy of them, as inheritrix, narratrix, perpetratrix, etc. In Geometry, words in -trix denote straight lines (linea being understood), as bisectrix, directrix; more rarely curves or surfaces, as indicatrix, tractrix. The suffix has occasionally been loosely used to form nonce-feminines to agent-nouns in -ter, as paintrix instead of the regular paintress. The commoner suffix in Eng. is -tress: see also -trice.