1) A muffin made chiefly of poo.
2) An obsolete computer monitor worth basically nothing. A computer monitor that should be thrown away and replaced with a much better, newer widescreen LCD monitor
3) An object or event that evokes negative feelings in someone.
4) (adj) Something or someone that is "just plain shitty", inferior.
1) "Mmmm, what's that smell?" "Oh I'm just baking some poo muffins"
2) Wesley should get a new monitor and get rid of his poo muffin.
3) Ahhhh... this is just poo muffin. I can't get tickets to see Primus on Friday.
4) You, dear sir, are plainly poo muffin.