What does " naughty " mean Mama?

After we got home from picking K up from school, he asked me two questions:

K: What does " whatever " mean Mama?
Mama: Where did you hear that word?
K: Shane said, " Whatever K." ( Shane is K's buddy at school)
Mama: It is a lazy word. There are strong words, and lazy words. You should try to use strong words. Try not to use lazy words. Whatever means it does matter.
K: What does " naughty " mean?
Mama: Where did you hear that word?
K: At school.
Mama: Who said that word?
K: Shane.
Mama: It means that you are doing something that you shouldn't be doing.
K: Oh, okay. I told Shane he is naughty. And Shane told me, whatever K.
Mama: Lol, okay. ( I'm not sure in what context he heard those words, but he sure remembered how he used them once he heard them! It's so interesting how much toddlers can pick up by just listening.)