What is "overreacting"

Usage examples of "overreacting".

Drusus had to himself, he disciplined his body to stillness and his anger to detachment, for he told himself that perhaps Cratippus was overreacting, that things might not be as bad as the servants obviously thought.

Char practiced putting up a mental barrier to keep her presence inconspicuous, but no one paid her any mind anyway, so she decided she was overreacting and quit it.