Someone who is from the United Kingdom. The term is typically used by people who don't know that 'British' is the proper way to refer to someone from the UK.
Jake: She used the word 'arse'
Pink: canadians say 'arse'
Leah: UKdians do too
Kenny: Leah, um, Dinner Friday night?
Pink: canadians say 'arse'
Leah: UKdians do too
Kenny: Leah, um, Dinner Friday night?
by artist6000 August 22, 2015