(Southern England) friend, acquaintance
Fancy a pint, me old mucker?
(British army) A comrade; a friendly, low-ranking soldier in the same situation.
Go and talk to your mucker!
A person who removes muck (waste, debris, broken rock, etc.), especially from a mine, construction site, or stable.
A low or vulgar labourer.
To scrape together (money, etc.) by mean labour or shifts.