kef \keyf\, noun:
1. A state of drowsy contentment
2. Also, keef. a substance, especially a smoking preparation of hemp leaves, used to produce this state.
I need not add that my kef—my noon rest, did not pass without interruption.
-- Karl Friedrich May, Through the Desert
...I tied on my hat and lit it down and held up my umbrella for shade, and fell into kef, being incapable of sustained thought.
-- William Cory, Extracts from the Letters and Journals of William Cory
Kef comes from the Arabic word kaif meaning “well-being or pleasure.”