A young cat, especially before sexual maturity (reached at about seven months).
"The playful kitten chased its own tail around the living room floor."
In plain English: A kitten is a very young cat that has not yet grown up to be an adult.
"The kitten chased its tail across the living room floor."
Usage: Use the noun form when referring specifically to a young cat under approximately seven months of age. The verb form is rarely used in everyday conversation and should be reserved for describing the act of giving birth rather than playing with or caring for one.
To give birth to kittens.
"The queen cat will soon begin to whelp her litter of kittens."
The word kitten comes from Middle English kitoun and is likely related to the Old French term for a young cat. While its exact origin remains unclear, it appears to be derived from an unattested Anglo-Norman form that was itself a diminutive of "cat.