terrible twos

[ ter-uh-buhl tooz ]

plural noun

1. a developmental phase in some toddlers characterized by temper tantrums, mood swings, defiance, and territorial behaviors:

   The terrible twos have reduced my kiddo’s vocabulary to two words, “mine” and “no!”

Word History and Origins

Origin of terrible twos¹

First recorded in 1950–55

Example Sentences

"It's still in its terrible twos," is how one Obama administration official puts it.

From The Daily Beast