c. 1300, "unfold, spread out, unfurl" (a banner, etc.), from Old French desploiir (Modern French déployer) "unfold, unfasten, spread out" (of knots, sealed letters, etc.), from Latin displicare "to scatter," in Medieval Latin "to unfold," from dis- "un-, apart" (see dis-) + plicare "to fold" (from PIE root *plek- "to plait").
Properly of sails or flags (and unconnected to play); meaning "reveal, exhibit, expose to view" is late 14c.; sense of "reveal unintentionally, allow to be seen" is from c. 1600. Related: Displayed; displaying.
1580s, "description," a sense now obsolete, from display (v.). Meaning "exhibition, a spreading of anything to the view," commonly with a suggestion of ostentation or striving for effect, is from 1680s. Meaning "presentation of electronic signals on a screen" is from 1945 in reference to radar, by 1960 of computers. Display-window is attested by 1893.
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."
mid-15c., ostentacioun, "ambitious display, pretentious show, display intended to evoke admiration or attract attention," from Old French ostentacion (mid-14c.) and directly from Latin ostentationem (nominative ostentatio) "showing, exhibition, vain display," noun of action from past-participle stem of ostentare "to display," frequentative of ostendere "to show" (see ostensible).
c. 1300, "ostentation and display," especially on parade, from Old French pompe "pomp, magnificence" (13c.) and directly from Latin pompa "procession, pomp," from Greek pompē "solemn procession, display, escort," literally "a sending," from pempein "to send," which is of unknown etymology. In Church Latin, used in deprecatory sense for "worldly display, vain show." The meaning "feeling of arrogance and vanity" (usually paired alliteratively with pride) is from early 14c.