A person from the telephone area code 905, which comprises North America's third-largest suburban sprawl, and surrounds the area code 416, Toronto's dense, cosmopolitan downtown core.
Used imply that someone is bland, boring, unsophisticated and/or ignorant.
See antonym: 416er
I can't stand this place; it's full of 905ers.
Why do 905ers wear all that cheaply made, ill-fitting American shopping-mall clothing?