Sleepy/ˈsliːpi/ Definition 1 of 3Pro Tip 1/3Physical State Use 'sleepy' to describe someone feeling the need to sleep, especially in informal settings. After watching the movie, I felt so sleepy. Pro Tip 2/3Observable Behavior 'Sleepy' describes someone who shows signs of tiredness, like yawning or drooping eyes. Her sleepy eyes made it clear she needed a nap. Pro Tip 3/3Subjective Feeling When feeling 'sleepy,' a person may not necessarily fall asleep but just feels the desire. Even though I'm sleepy, I have to finish my homework.