merx.

From Proto-Italic *merks (compare Faliscan 𐌌𐌄𐌓𐌂𐌖𐌉 (mercui, dative), Oscan 𐌌𐌄𐌓𐌉𐌊𐌖𐌉 (merikui, dat.sg.), names of deities), of uncertain etymology. De Vaan relates this word to Mercurius, deriving them both from a root referring to various aspects of economics, which he presumes to have an Etruscan origin. However, in the 2020s, Nikolaev and Matasović independently proposed Indo-European etymologies for merx. Both derivations assume that the simple -c- in the oblique cases was analogically levelled based on the nominative singular, as all velars merged to *-k- when immediately preceding the nominative singular *-s in Italic. * Nikolaev reconstructs Proto-Indo-European *merkʷ-, relating merx to Ancient Greek μάρπτω (márptō, “to take hold”) and Tocharian A märk- (“to take away”). * Matasović instead derives this word from a root *merǵ- (“to divide”), whence also margō (“border”), Proto-Celtic *mrogis, Proto-Germanic *markō, and Persian مرز (marz), the verbal sense of which survives in Hittite 𒈥𒀝𒍣 (mar-ak-zi /⁠marktsi⁠/, “to cut up, separate, divide, distribute”). The connection to Hittite was in fact already suggested by Puhvel (2004). This root *merǵ- may itself be an extension of *mer- (“to divide, apportion, allot”), for which see Latin mereō. Compare typologically Mongolian зах (zax, “border, boundary, edge; market, bazaar”).