Feeling like you want to sleep or feeling like you need to sleep.
Feeling sleepy is usually a very calm and relaxed feeling.
Examples:
I feel sleepy after lunch.
The baby looks very sleepy.
She is always sleepy in the morning.
The cat looks very sleepy after eating.
I am so sleepy, I could fall asleep standing up!
The bear is very sleepy and wants to take a nap.