Be agreeably sleepy? (3)
I believe the answer is:
nod
This clue is a double definition.
'be agreeably' is the first definition.
(I've seen this before)
'sleepy?' is the second definition.
(I've seen this before)
(Other definitions for nod that I've seen before include "Sign of assent or salutation" , "slight bow" , "Show agreement (or sleepiness?)" , "Indicate agreement (or sleepiness!)" , "Where Cain went to" .)