An abbreviation for "West Coast Offense", an offense created by legendary 49ers coach Bill Walsh which has been passed on and tweaked by many in his coaching tree.
A WCO is the offense Gary Kubiak installed to cripple the Denver Broncos prolific offense. He tried to slow down Peyton Manning for years as the Texans coach. He finally accomplished that as the Broncos head coach. Thankfully for Broncos fans the team was able to overcome Kubiak to win Super Bowl 50