quintain (n.)

"target for tilting and jousting practice," c. 1400 (in Anglo-Latin from mid-13c.), from Old French quintaine or directly from Medieval Latin quintana; perhaps from Latin quintana "of the fifth" (from PIE root *penkwe- "five"), which as a noun meant "the business part of a camp," a street where the market and forum were located, on the supposition that this was where military exercises were done [OED].

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