(UK, slang) To betray by informing on.
(UK, slang) To betray by informing on.
Add your own interpretation of "grass up".
Regional slang from around the English-speaking world — British, Australian, Irish, Caribbean, Nigerian, Filipino, AAVE, and the hyphenated-English dialects that make the internet sound local.
See all Regional & Other slang on Slangora.
Browse all slang words starting with G.