Noun

1. Abbreviation of cockatoo, especially when talking to such a bird, as in "hello cocky".

   2005: Visit the local store at Coles Bay and you're greeted by a talking cocky called Jim. — Australian Broadcasting Commission, The World Today program, Town seeks environmental accreditation, 5 August 2005 http://www.abc.net.au/worldtoday/content/2005/s1431391.htm

2. A farmer.

   And stories in the bush may not seem relevant in the big smoke, but try telling that to a cocky. — Shelley Horton, Australian Broadcasting Commission Media Dimensions program, episode 15 http://www.abc.net.au/dimensions/media/transcripts/s420757.htm

Adjective

1. overly self-confident up to a point where you're kidding yourself of your abilities.