Meaning to err greatly. Literally meaning to accidently achieve an orgasm when fooling around to get your sausage up in a girls guts. Hence, a catostrophic fuck up.
ex 1: We really can't screw the pooch in the 4th quarter, boys. 
ex2: guy1-" I was so nervous with sheniqua last night that i screwed the pooch."
guy2- " ouch dude, ouch.
guy1-" ehhhh, it was good for me."
ex2: guy1-" I was so nervous with sheniqua last night that i screwed the pooch."
guy2- " ouch dude, ouch.
guy1-" ehhhh, it was good for me."
by Ollie Vector November 20, 2006
 Get the screw the poochmug.
Get the screw the poochmug. To have made a massive, catastrophic blunder. An extension of the more common "screwed the pooch," which adds a more severe consequence to the metaphorical action.
Since invading Iraq, President Bush and his advisors have really screwed the pooch and knocked it up.
by ElOjo January 9, 2008
 Get the screwed the pooch and knocked it upmug.
Get the screwed the pooch and knocked it upmug. You've fucked up so bad the only real way of describing it is as though you have fucked a dog and have to explain it to your parents.
Morty: awe geez I really screwed the pooch on that one.
Rick: nice going morty, snowball will definitely neuter you after that stunt.
Rick: nice going morty, snowball will definitely neuter you after that stunt.
by The_law21 November 5, 2019
 Get the Screwed The Poochmug.
Get the Screwed The Poochmug.