Definition of sleepiness

The word "sleepiness" has its roots in Old English and Middle English. The earliest recorded use of the word "sleep" dates back to around 700 AD, and it was derived from the Proto-Germanic word "slēpiz", which was also the source of the Modern German word "Schlaf". Over time, the English language developed the synonymous term "drowsiness", which referred to a state of feeling heavy-eyed or inclined to sleep. The current form of the word "sleepiness" emerged in the 15th century, likely as a combination of the noun "sleep" and the suffix "-ness", which forms a noun indicating a quality or state. The first recorded usage of "sleepiness" was in the 15th-century treatise "The Canterbury Tales" by Geoffrey Chaucer. Since then, "sleepiness" has been used to describe the state of feeling lethargic or drowsy, often due to a lack of sleep or fatigue.