Etymology
Advertisement
plaid (n.)

1510s, "garment consisting of a long piece of woolen cloth, often having a tartan pattern, traditionally worn in Scotland," from Scottish, from or related to Gaelic plaide "blanket, mantle," a word of uncertain etymology, perhaps a contraction of peallaid "sheepskin," from peall "skin," from Latin pellis (but OED finds this "phonetically improbable").

It is a large rectangular piece of woolen stuff, and is worn in Scotland by both sexes for warmth and for protection against the weather. It is a special dress of the Highlanders, and forms part of the uniform of certain infantry regiments in the British army. A variety of the plaid is called maud. [Century Dictionary]

The wearing of it by males was forbidden by Act of Parliament, under penalty of transportation, 1746-82. The meaning "a pattern of bars crossing each other at right angles" is by 1890. As an adjective, "ornamented with a pattern of bars or stripes of color crossing one another at right angles," c. 1600, from the noun.

Related entries & more 
Advertisement
plait (n.)

late 14c., pleit, "a fold, a crease, a flattened gather made by doubling cloth or similar fabric in narrow strips upon itself," also "interlaced strands of hair," from Anglo-French pleit, Old French ploit, earlier pleit, "fold, manner of folding," from Latin plicatus, past participle of plicare "to lay, fold, twist" (from PIE root *plek- "to plait").

Related entries & more 
plait (v.)

late 14c., pleiten, "to fold (something), gather in pleats, double in narrow strips," also "to braid or weave (something)," from plait (n.) and also from Old French pleir "to fold," variant of ploier, ployer "to fold, bend," from Latin plicare "to fold" (from PIE root *plek- "to plait"). Related: Plaited; plaiting.

Related entries & more 
complect (v.)

1520s, "to embrace;" 1570s, "to weave together;" from Late Latin complectus, past participle of complectere "to embrace, encircle," from Latin com "with" (see com-) + plectere "to plait," from suffixed form of PIE root *plek- "to plait." Related: Complected; complecting.

Related entries & more 
*plek- 
Proto-Indo-European root meaning "to plait." It is an extended form of root *pel- (2) "to fold."

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."
Related entries & more 
Advertisement
biplicate (adj.)
"doubly folded," 1840 in botany, from bi- "two" + Latin plicare "to fold" (from PIE root *plek- "to plait").
Related entries & more 
gather (n.)
"plait or fold in cloth," 1660s, from gather (v.).
Related entries & more 
plash (v.2)

"to interlace, to bend and interweave the branches or twigs of," late 15c. (implied in plashing), from Old French plaissier, from Latin plectere "to plait," from suffixed form of PIE root *plek- "to plait." Related: Plashed.

Related entries & more 
implex (adj.)
"intricate, complicated," 1710, from Latin implexus "interwoven, entwined," past participle of implectere, from assimilated form of in- "in" (from PIE root *en "in") + plectere "to plait, twine, braid" (from suffixed form of PIE root *plek- "to plait"). Used by 18c. critics in reference to plots.
Related entries & more 
plat (v.)

"to interweave," late 14c., a variant of plait (v.). Related: Platted; platting.

Related entries & more