cocky1

[kok-ee] /ˈkɒk i/
adjective, cockier, cockiest.
1.
arrogant; pertly self-assertive; conceited:
He walked in with a cocky air.
Origin
1540-50; cock1 + -y1
Related forms
cockily, adverb
cockiness, noun

cocky2

[kok-ee] /ˈkɒk i/
noun, plural cockies.
1.
Australian.
  1. cockatoo (def 1).
  2. cockatoo (def 2a).
2.
cockatiel.
Origin
1885-90; cock(atoo), cock(atiel) + -y2

cocky3

[kok-ee] /ˈkɒk i/
verb (used without object), cockied, cockying. Newfoundland.
1.
copy (def 19).
Origin
apparently a playful alteration, by association with cocky1
British Dictionary definitions for cocky

cocky1

/ˈkɒkɪ/
adjective cockier, cockiest
1.
excessively proud of oneself
Derived Forms
cockily, adverb

cocky2

/ˈkɒkɪ/
noun (Austral, informal) (pl) cockies
1.
short for cockatoo (sense 2)
2.
a farmer whose farm is regarded as small or of little account
Word Origin and History for cocky
adj.

"arrogantly pert," 1768; originally "lecherous" (1540s); from cock (n.1) + -y (2). Related: Cockiness.