Green’s Dictionary of Slang

doggin n.

[dog (end) under dog n.2 ]

(N.Z.) a cigarette end.

[NZ]J. Henderson Gunner Inglorious 146: By crikey, we used to say, wouldn’t it be great to collect all the cigarette butts chucked away at the old cinemas back home? Remember all the ‘doggins’ round the lounges and entrances?