Here are some synonyms for drowsy:
* Sleepy
* Tired
* Lethargic
* Dozy
* Somnolent
* Heavy-eyed
Examples of how to use "drowsy" in a sentence:
* I felt drowsy after a long day at work.
* The warm sun made me feel drowsy.
* The medication made me feel drowsy, so I couldn't drive.
* The baby was so drowsy that he fell asleep in his mother's arms.