half-asleep vs sleepy

half-asleep

• Showing signs of being asleep or very sleepy, as not demonstrating full energy or attention. 

sleepy

• Tired; feeling the need for sleep. 

• Quiet; without bustle or activity. 

• Tending to induce sleep. 

• Suggesting tiredness. 

• Dull; lazy. 

• The gum that builds up in the eye; sleep, gound.