ensis.

Uncertain. Perhaps cognate with Palaic 𒄩𒅆𒄿𒊏𒄠 (ḫa-ši-i-ra-am, “dagger”), Sanskrit असि (así, “sword”), and Ancient Greek ἄορ (áor, “(hanger for a) sword”). De Vaan reconstructs Proto-Indo-European *h₁ensi- (“sword, large knife”); however, the ḫ- of the Palaic form is incompatible with an initial *h₁-. Yet, a reconstruction *h₂n̥sis is problematic for Latin as it would violate Rix's Law, according to which the outcome **ānsis would be expected (compare Latin ambi-, from *h₂m̥bʰí). The linguist Stefan Höfler, however, contents the operation of Rix's Law in Latin, citing forms such as ēnsis and the possible derivation from *h₂n̥sís as evidence. Another possibility is that the term could maybe reflect a paradigm *h₂ḗnsis ~ *h₂n̥séys, in which case the lengthened grade would have been generalized in Italic. Ultimately, according to De Vaan, all alleged Indo-European cognates are uncertain. Schrijver argues that words denoting material objects are easily borrowed, allowing for the possibility that the resemblance between this word and other Indo-European forms is partially coincidental. Regardless, the EIEC—which reconstructs the PIE form as *h_(2/3)ṇsis—still argues that the form likely dates back to Proto-Indo-European.