What is Pie-eater?
1.
Person from Wigan.
Nothing to do with the large number of pies eaten in Wigan but to do with a miner's strike in the 1920's when all the pits in WIgan and Leigh went on strike. The Wiganers went back and broke the strike, the "Leythers" continued to strike and got better pay and conditions. Therefore the Wiganer's had to "eat humble pie"... so it's a term of abuse from Leythers to Wiganers. The hostility between the two towns stretches back hundreds of years to the civil war when Wigan was Royalists and Leigh were Parliamentarian and continues to this day.
"The 'pie-eaters' aren't as good a Super League these days"
"This will be the 'pie-eaters' last year in the Premiership"
See
2.
A person from Wigan, supporter of Wigan Warriors Rugby league team, or (pl.) the team itself. Possibly from Australian slang, where it means a lower-class person, but Wigan is noted for its fine pies as well as its rugby league players, some of whom are Australian.
'I've got a ticket for the Challenge Cup final, but I'll have to sit with the pie-eaters'
'We're away to the pie-eaters next Sunday'