Somnolent (adjective)

1. Feeling or showing a tendency to want to sleep; drowsy or sleepy.
2. Tending to cause drowsiness or sleepiness; soporific.
3. Lacking energy or enthusiasm; sluggish or listless.

Origin:

The word 'somnolent' is derived from the latin word 'somnus' meaning 'sleep', 'somnolentus' meaning 'drowsy'.

Examples:

1. The warm sun and the sound of the waves made the beachgoers feel somnolent.
2. The long flight was very tiring, and the passengers felt somnolent and drowsy by the time they landed.
3. The sedative effect of the medicine made him feel somnolent and sluggish.
4. The somnolent atmosphere of the library made it hard for her to stay awake and study.
5. The somnolent pace of the movie was criticized by many viewers for being too slow and boring.