An expression that means 'unexpected semi erection'. To have a Barnsley. Derived from when Barnsley FC unexpectedly beat Chelsea to go through to the Semi finals. Used for when one is aroused by something one would not have previously expected to be aroused by. Also used to describe an erection that has just come from nowhere.
James: Watching Susan Boyle has given me a Barnsley..
Greg: Get up Joel, we gotta get to class..
Joel: Give it a minute, I got a Barnsley