piquant adj.

"weapon with a long shaft and a pointed metal head," 1510s, from French pique "a spear; pikeman," from piquer "to pick, puncture, pierce," from Old French pic "sharp point or spike," a general continental term (Spanish pica, Italian picca, Provençal piqua), perhaps ultimately from a Germanic [Barnhart] or Celtic source (see pike (n.2)). An alternative explanation traces the Old French word (via Vulgar Latin *piccare "to prick, pierce") to Latin picus "woodpecker." No doubt, too, there is influence from pike (n.1), which by 1200 had a sense of "spiked staff."

"Formerly the chief weapon of a large part of the infantry; in the 18th c. superseded by the bayonet" [OED]; hence old expressions such as pass through pikes "come through difficulties, run the gauntlet;" push of pikes "close-quarters combat." German Pike, Dutch piek, Danish pik, etc. are from French pique.

"piquant quality; pleasing cleverness or raciness; keenness, sharpness, tartness," 1660s, from piquant + abstract noun suffix -cy.

1590s, "sharp and painful, poignant, piercing," originally figurative, of pain or grief, from Latin pungentem (nominative pungens), present participle of pungere "to prick, pierce, sting," figuratively, "to vex, grieve, trouble, afflict" (from suffixed form of PIE root *peuk- "to prick"). For sense development, compare piquant; sharp (adj.).

Meaning "having powerful odor or taste, sharply affecting the sense of smell" is recorded by 1660s; in reference to writing, etc., "sharply affecting the mind, curt and expressive" is by 1850. The literal sense of "sharp, pointed" (c. 1600) is very rare in English and mostly limited to botany.

Middle English and early Modern English also had a now-obsolete verb punge "to prick, pierce; to smart, cause to sting," from Latin pungere. Related: Pungently.