a picture, description, or imitation of a person in which certain striking characteristics are exaggerated in order to create a comic or grotesque effect.
You can infer that the writer (in context) is either talking about a literal caricature (a picture, description, or imitation of a person in which certain striking characteristics are exaggerated in order to create a comic or grotesque effect) or (in a metaphor) an exaggeration of a truth or situation.
