adj. 25B6; adjective
she felt very sleepy : DROWSY, tired, somnolent, languid, languorous, heavy-eyed, asleep on one's feet; lethargic, sluggish, enervated, torpid; informal dopey; poetic/literary slumberous.
the sleepy heat of the afternoon : SOPORIFIC, sleep-inducing, somnolent.
a sleepy little village : QUIET, peaceful, tranquil, placid, slow-moving; dull, boring.
awake, alert.