An unspecified, vaguely disreputable person.
A funny person.
A friendly unit that acts as a suspected hostile unit in a military excercise.
A jester.
A person who makes jokes.
A clause in a contract that undermines its apparent provisions.
A man.
A playing card that features a picture of a joker (that is, a jester) and that may be used as a wild card in some card games.
An impish or playful person.
One who plays tricks or pranks on others.
A fraud (person who performs a trick for the purpose of unlawful gain).
Any of numerous figures featuring in various mythologies and folk traditions, who use guile and secret knowledge to challenge authority and play tricks and pranks on others; any similar figure in literature.
One who performs tricks (parts of a magician' act or entertaining difficult physical actions).