You know that kid you see in a supermarket with his/her mom, and the kid is all like: "I don't like that", and starts to scream? What is a good word or slang term for that?
a : child; specifically : an ill-mannered annoying child a spoiled brat
b : an ill-mannered immature person
While there are many other terms for this idea, this one is commonly understood in American English.
Not used so much as a term for the person, but the development stage of that toddler.
Charlie is in his terrible twos, and it's been so difficult!
Dictionary.com defines as:
"A stage of development in which toddler behavior is a particular challenge."