sleepiness sleepily • sleeping · · · Info · Definitions · Synonyms · Antonyms · Characters · · sleepiness · · Text Latin · · Script 10 · · Length Definitions · · · (noun) a very sleepy state. Synonyms: drowsiness, somnolence. Example: "Sleepiness causes many driving accidents." · · Noun Definition 1 Synonyms · · · drowsiness · · Synonym 1 somnolence · · Synonym 2 Antonyms · · · wakefulness · · Antonym 0 sleeplessness · · Antonym 1 Characters · · e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E p latin small letter p U+0070 s latin small letter s U+0073