Etymology Part I: Knackered

I have some particular pet phrases, some of which I've been using for years without any indication that I'm using them correctly - time to find out! Being fond of K words, I'm starting with knackered.

"Knackered" is an expression (primarily British) meaning "tired" or "worn out". A knacker, I've learned, is a person who buys old horses that are too worn out to be used for work. A knackery is a horse slaughterhouse. Several online sources mention that the word is "probably of Scandanavian origin", though none offer a related Scandanavian word and the sites are probably all citing each other.

I learned a new definition too: knacker is a derogatory term in Ireland. It once referred to gypsies, and is now used to describe transient, uh, underachievers. Have not yet been able to determine where the word became attached to the gypsies - did they buy old horses? Sell knick-knacks? Steal stuff?

"Knack" (meaning trick or special skill), as it turns out, has a different root. Different source cite knakke from Middle English, cnacken from Middle Dutch, and knachen from German (the last two meaning "to crack"). A 1737 Dictionary of Thieving Slang lists a "knack-shop" as a shop where one can get tools for picking pockets.

Totally knackered by now - off to bed.