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.
knee jerk (knee reflex) a kick reflex produced by sharply tapping the patellar ligament. To test this reflex, the lower part of the leg is allowed to hang relaxed (such as by crossing the legs at the knees) and the examiner taps the ligament below the patella with a small rubber hammer.