-plex

Meaning

1. morphemeone terminationsuffixCreates adjectives specifying the number of times, -fold
   sem- (“one”) → simplex (“onefold, single, simple”)
   tri- (“three”) → triplex (“threefold”)

Origins

Disputed. *Possibly from Proto-Italic *-pleks, from Proto-Indo-European *pleḱ- (“to plait, to weave”), making it equivalent to plicō (“to fold”) + -s. * Possibly from Proto-Italic *-plaks, with regular reduction of Proto-Italic *-a- to Latin -e- in a non-initial closed syllable. * In either case, it may ultimately derive from an extension of Proto-Indo-European *pel- (“to fold”). Compare -plus. Potential cognates include Umbrian -𐌐𐌋𐌀𐌊 (-plak), found in 𐌕𐌖𐌐𐌋𐌀𐌊 (tuplak), and Ancient Greek -πλαξ (-plax), found in δίπλαξ (díplax) and τρίπλαξ (tríplax). * De Vaan 2008 derives Latin -plex from Proto-Italic *-pleks, from the e-grade of the root *pleḱ-, and Greek -πλαξ (-plax) from Proto-Indo-European *-pl̥ḱ-, the zero-grade ablaut variant of the same root. De Vaan considers the meaning and etymology of the Umbrian form to be unclear. (At the same time, De Vaan reconstructs simplex as coming from Proto-Italic *sm̥-plak-s.) Beekes thinks the Latin, Umbrian, and Greek endings can all be derived from the root *pleḱ-. * The Umbrian form suggests Proto-Italic *-plaks, which complicates the etymology from *pleḱ- (“to plait, to weave”) (since zero-grade *-plḱ-s would be expected to yield Proto-Italic *-polk-s; cf. *stl̥-tós > *stoltos, *wr̥t-tós > *worssos, *pr̥sḱéti > *porsket). Flemestad and Olsen 2017 treat all three of duplex, 𐌕𐌖𐌐𐌋𐌀𐌊 (tuplak), and δίπλαξ (díplax) as cognates, and prefer to derive them from the root *pel- (“fold”) combined with a suffix *-ak-. * Some argue that Greek -πλαξ (-plax) is not from *pleḱ- (“to plait, to weave”), but from an unrelated root found in πλάξ (pláx, “surface”), which van Beek 2022 identifies as coming from *plek‑ (“to strip, flay”). * Coleman 1992 suggests duplex and 𐌕𐌖𐌐𐌋𐌀𐌊 (tuplak) might be derived from Proto-Indo-European *pleh₂- (“flat”), the root of plānus, which he considers to be an extension of *pel-.