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rat

1 rat /ˈræt/ noun
plural rats
1 rat
/ˈræt/
noun
plural rats
Britannica Dictionary definition of RAT
[count]
: a small animal that has a pointed nose and a long, thin tail
see picture at rodent
informal
: a person who is not loyal or who cannot be trusted
: a person who is bad or cruel
US, informal : a person who spends a lot of time in a specified place

smell a rat

informal
: to think or suspect that something is wrong about a situation
see also pack rat, rugrat
2 rat /ˈræt/ verb
rats; ratted; ratting
2 rat
/ˈræt/
verb
rats; ratted; ratting
Britannica Dictionary definition of RAT
informal
: to tell someone in authority (such as the police) about something wrong that someone has done : to betray someone
[no object]
often + on
[+ object]
(US) + out