It means that he is despicable; he's done something horrible like betray someone. Rats are typically seen as "dirty" animals, so the allusion here is that he is like a rat and has no morals.
It means to tell or spy on someone. Used in a sentence, I am not going to rat on my friends,i don't like doing that.
It was in 1960 in America
Yew are
Gagsters - 2003 Dirty Rat was released on: USA: 2004
i smell a rat is an idiom which means to dectect, suspect or to find the tricks of some on. Ex. I smell a rat of JOHN against Shaun.
kourtney wisniewiski
Rufus and hes a naked mole rat
Jimmy Cagney
Jimmy Cagney
One idiom found in the book "Delirium" by Lauren Oliver is "smell a rat," which means to suspect that something is wrong or suspicious.
Billy the Exterminator - 2009 Dirty Rat 4-8 was released on: USA: 23 August 2011
Kenan and Kel - 1996 You Dirty Rat 3-10 was released on: USA: 19 December 1998