Meaning of the word "drift off" in English

What does "drift off" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

drift off

US /drɪft ɔːf/
UK /drɪft ɒf/
"drift off" picture

Phrasal Verb

to gradually fall asleep

Example:
I was just beginning to drift off when the phone rang.
The lecture was so boring that I found myself drifting off.