Are you sleepy? Maybe you need to doze a little. To doze is to sleep lightly or to take a nap.
To doze is to just have a little sleep: either a short nap or a very light snooze. Since doze and snooze almost rhyme — and snoring sounds a little like ZZZZZZZZZZZ — the letter Z might be a good way to remember this word. Just make sure you don't "doze off" in class.