Other forms: overreacting; overreacted; overreacts
To overreact is to respond to something in an overly excited, angry, or fearful way. If you're pretty sure your dad will overreact when he hears about your fender bender, you might want to tell your mom first.
Whenever someone reacts more emotionally than seems appropriate, they overreact. You might overreact to a happy plot twist in your favorite TV show by cheering and jumping up and down — and a city bus driver might overreact to a passenger listening to loud music by pulling the bus over to the side of the road and turning to yell angrily. Overreact was first used in the 1960s, probably by historian and literary critic Lewis Mumford.