Definition of twocker in US English:

twocker

(also twoccer, TWOCer, twocer)

noun

British
slang, police slang
  • A car thief, especially one who steals for the purpose of joy-riding.

Origin

1990s; earliest use found in The Guardian. From twoc + -er.

Pronunciation

twocker

/ˈtwɒkə/