Synonyms of the word 
SLEEPINESS → DROWSINESS - SOMNOLENCE
sleepiness
- n. The property of being sleepy.
drowsiness
- n. State of being drowsy.
somnolence
- n. a state of drowsiness or sleepiness.
If you are interested in words, visit the following sites :
- wiktionary.org/sleepiness For complete definition of a word
- 1word.ws/sleepiness to play with words, suffixs, prefixs, etc.