Any theories for the term “whack job”? Is it related to wacky, and should it be “wack job”?

Bandito could answer that for you, as his avatar evidently survived the annual cull of seal pups, albeit with severe facial injuries.

Alternative spellings

  * wackjob

Etymology

  * whack(y) + job(bie)

(colloquial, pejorative) A crazy, possibly dangerous, person.

http://en.wiktionary.org/wiki/Whack_job

whack (informal):

— PHRASES out of whack chiefly N. Amer. & Austral./NZ not working. top (or full) whack chiefly Brit. the maximum price or rate.

— ORIGIN imitative.

http://www.askoxford.com/concise_oed/whack?view=uk

whack [ wak, hwak ]

an attempt at doing something ( informal )

“That looks like fun - can I take a whack at it?”

- Early 18th century. Probably an imitation of the sound

http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861712527

Etymology: probably imitative of the sound of a blow

Date: 1719

chiefly British : to get the better of : defeat

slang : murder , kill

http://www.merriam-webster.com/dictionary/whack

Etymology - Onomatopoeic.

Homophone -  wack

Derived terms

  * out of whack
  * whack the illy
  * whacky

http://en.wiktionary.org/wiki/whack?rdfrom=Whack

“to strike sharply,” 1719, probably of imitative origin. The noun is from 1737. The word in out of whack (1885) is perhaps the slang meaning “share, just portion” (1785),
which may be from the notion of the blow that divides, or the rap of the auctioneer’s hammer.

http://www.etymonline.com/index.php?term=whack

http://www.answers.com/whack

http://www.thefreedictionary.com/whack

http://www.peevish.co.uk/slang/w.htm