When a group of friends find a dead bird (famously a grouse) the day after the night before whilst still relatively intoxicated and decide t'would be a good idea to use it to cause mischief and/or shennanigans. This could involve a good slap or as it should be known a grousin' to an unsuspecting pedestrians face! Alternatively you could dump it in a public urinal or in your flatmates frying pan. It helps if you drive a soft top car with the roof down playing the greatest hits of Justin Bieber and Baby Alice.
Billy Joel: "Shit dude, me and the guys got totally wasted last night and this morning we went for a bit of grousin' like you do."
Steve: "Grousin', what's that?"
Billy Joel: "You know, when you find a dead bird by the side of the road and use it to cause all sorts of crazy mischief!"
Steve: "Dude wtf is wrong with you? I hope you get caught"
Billy Joel: "I really don't know man, I hope we do too otherwise we'll never learn!"
Steve: "Grousin', what's that?"
Billy Joel: "You know, when you find a dead bird by the side of the road and use it to cause all sorts of crazy mischief!"
Steve: "Dude wtf is wrong with you? I hope you get caught"
Billy Joel: "I really don't know man, I hope we do too otherwise we'll never learn!"
by jMiR October 20, 2010
Informally short for ones second cousin which is one’s parents first cousin, as in “Great Cousin”. (Like one’s parents aunt is ones Great Aunt ect.)
by TrashPanda420311 April 2, 2022