Drowsy (adjective)

1. Feeling sleepy or inclined to sleep.
2. Lacking energy or alertness.

Origin:

Middle english: from old english drūsig "drowsy," from drūsian "to slumber," of germanic origin; related to german trügen "to cheat," also to true.

Examples:

1. He felt drowsy after the heavy meal.
2. The medicine made her drowsy and she couldn't stay awake.