Green’s Dictionary of Slang

duck n.6

[late 19C–1950s] an evasion.

In phrases

cop a duck (v.)

[1970s] (US) to hide, to stay out of the way.

do a/the duck (v.) (also do a duckaway)

[late 19C-1960s] to escape, to run off.

do a duck in (v.)

[1910s] (Aus.) to make an appearance.

fake the duck (v.)

[mid–19C] (UK Und.) to perform, to do something (duplicitous).

play the duck (v.)

1. [mid-17C] to behave in a cowardly manner.

2. [1920s+] to avoid.