It's a combination of "grub" and "rubbish", making another word for junk food.
I don't feel like cooking tonight. Let's just go out and pick up some grubbish.
de luckysocks113 6 août 2014
1 more definition
A mix of garbage and rubbish, usually in the context of source-code.
Fix that routine- it's absolute grubbish.
de Rev. Five 25 mai 2005