The use of âholidayâ to mean âa missed spotâ appears to be that rarity in English etymology, a word or phrase that actually has a nautical origin. The original use of âholidayâ in the âmissed a spotâ sense, back in the 18th century, was in reference to crew members painting the decks of a ship or âpayingâ (sealing seams with tar or pitch) its hull.
The knee jerk reflex is when a tendon above the kneecap is tapped with a reflex hammer, which causes the whole leg to involuntarily jerk.
Synonym(s): knee jerk, knee reflex, knee-jerk reflex, patellar tendon reflex, quadriceps reflex. n. A reflex contraction of the quadriceps muscle resulting in a sudden involuntary extension of the leg, produced by a sharp tap to the tendon below the patella; patellar reflex.