Why do Aussies use "cactus" to mean "dead," "useless," or "broken"?

This bloody washing machine is cactus!

Glossaries / dictionaries of Australian slang (like this one, and this one) list cactus as meaning "dead, useless, or broken."

How did this usage come about?

Solution 1:

Cactused: (from Your.dictionary)

• (Australia, slang) Broken; ruined; no longer working, more recently especially related to a technical system. My computer is cactused!

Cactus: (from Wikipedia)

• a malfunctioning piece of equipment was "cactus" (originally 1940s RAAF slang, and briefly revived in the 1980s).

The story appears to come from the:

• Prickly Pear Cactus (native South American), was brought to Australia in 1788 on the First Fleet. It became a pest, quickly overrunning many thousand acres of farmland.

• To combat it, the caterpillar/moth Cactoblastis (also South American native), was introduced in the 1920s.

• Wildly successful, it practically eliminated the spiny exotic in a few years. defeated. Hence, CACTUS, in Australian slang, means: beaten, finished, ruined, kaput etc.e.g. Jim threw just two punches, and Jack was cactus.

(From www.answers.com)

Solution 2:

I would like to suggest a different origin for 'cactus' - for several reasons. First, the slang term apparently originated in RAAF in the 1940s (according to the Wikipedia quote above), well after the introduction of Cactoblastis, and with no obvious connection to it. Second, in my experience the weed is always called 'prickly pear' in Australia, never 'cactus'. Thus I believe that 'cactus' is simply a euphemism for 'f*cked', chosen because of it sounds similar, but is innocuous (like 'darned' instead of 'damned'). During my apprenticeship in Sydney in the 1970's this was often spelled out, e.g. "It's cactus fuctus".