word-forming element, from Latin -plex, from PIE root *plek- "to plait." De Vaan writes, "Probably, duplex was the archetype of this category of compounds."
Entries related to -plex
It forms all or part of: accomplice; application; apply; complex; complexion; complicate; complication; complicity; deploy; display; duplex; duplicate; duplicity; employ; explicate; explicit; exploit; flax; implex; implicate; implication; implicit; imply; multiply; perplex; perplexity; plait; plash (v.2) "to interlace;" pleat; -plex; plexus; pliable; pliant; plie; plight (n.1) "condition or state;" ply (v.1) "work with, use;" ply (v.2) "to bend; ply (n.) "a layer, fold;" replica; replicate; replication; reply; simplex; splay; triplicate.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit prasna- "turban;" Greek plekein "to plait, braid, wind, twine," plektos "twisted;" Latin plicare "to lay, fold, twist," plectere (past participle plexus) "to plait, braid, intertwine;" Old Church Slavonic plesti "to braid, plait, twist," Russian plesti; Gothic flahta "braid;" Old Norse fletta, Old High German flehtan "to plait;" Old English fleax "cloth made with flax, linen."
1875, in reference to telegraph systems in which four messages can be wired simultaneously, from quadru- + -plex. In classical Latin, quadruplex meant "fourfold, quadruple," as a noun, "a fourfold amount." Related: Quadruplicity "fourfold nature," 1580s, from Latin quadruplicitas, noun of quality from quadruplex.