Totally means completely, entirely, or in every way possible. When something is totally finished, there's nothing left to do. When you're totally sure about an answer, you don't have even a tiny doubt. When your room is totally clean, every corner is spotless.

The word adds emphasis to show that something is 100% true, with no exceptions or halfway measures. If your shirt gets totally soaked in the rain, it's wet through and through, not a drop of dry fabric remaining. If you totally forgot about your homework, it was completely gone from your mind. You didn't remember it at all until someone reminded you.

Kids often use totally in conversation to show strong agreement: “Do you want pizza for dinner?” “Totally!” In this casual use, it means “absolutely yes” or “I completely agree.” You might also hear someone say they totally understand something, meaning they grasp it fully, or that they're totally exhausted, meaning they have zero energy left.