Green’s Dictionary of Slang

cocky n.2

also cockie
[cockatoo n.2 (3)]

1. a prisoner or ex-prisoner who had been confined on Cockatoo Island.

2. [mid-19C+] a small farmer.

3. in attrib. use of sense 2.

4. [1920s+] a small farmer or large landowner, as modified by the crop in which they specialize, e.g. wheat cocky, cow cocky under cow n.1 etc.

5. [1950s] a lookout at a two-up game.

In derivatives

cockydom (n.)

[late 19C+] (Aus.) the world of small farmers.

In compounds

cocky’s coal (n.)

[1900s–40s] (Aus.) dry corncobs used as fuel.

cocky’s crow (n.) [pun on SE cock’s crow]

[20C+] (Aus.) dawn.

cocky’s delight (n.) (also cocky’s joy)(Aus.)

1. [20C+] molasses, treacle or golden syrup.

2. [1970s] wire fencing.

cocky’s friend (n.)

1. binder twine.

2. [1930s] (Aus.) fencing wire.

cocky’s horror (n.)

[2000s] (N.Z.) grease, oil.

cocky’s string (n.)

[20C+] (Aus.) fencing wire, which has a variety of everyday uses in addition to marking boundaries.

In phrases

like the cocky on the biscuit tin (also like the bird…) [the old tins of Arnott’s biscuits had a picture of a cockatoo, which was thus ‘on’ the tin but not ‘in’ it]

[1940s+] (Aus.) useless, impotent, a non-participant.

sheep-cocky (n.)

[late 19C+] (Aus./N.Z.) a small-scale sheep farmer.