Definition of hooligans:
(n) :
(informal, attributive) A young person who causes trouble or violence, typically as a member of a gang or other group.
(n) :
(slang, US) A member of the United States Coast Guard.
(v) :
(intransitive) To act as a hooligan (etymology 1, sense 1).
(v) :
(transitive, by extension) To treat (a person) roughly.
(n) :
A type of fish, an anadromous smelt, Thaleichthys pacificus, found in the North Pacific.
(n) :
Ellipsis of football hooligan. [(UK) A violent football (soccer) fan who routinely fights with supporters of opposing teams and/or with police, often the member of a firm.]