I. cop ‧ y ‧ cat 1 /ˈkɒpikæt $ ˈkɑː-/ BrE AmE noun [countable]
informal someone who copies other people’s clothes, behaviour, work etc – used by children to show disapproval
II. copycat 2 BrE AmE adjective
copycat crime/attack etc a crime, attack etc which is similar to a famous crime that another person has committed:
Crime reports in newspapers often encourage copycat crimes.