The word **kitten** has a straightforward but well-traveled history. It entered Middle English in the late 1300s as *kitoun* or *kytoun*, borrowed from Anglo-Norman French *kitoun*, a diminutive of *chat* (cat). The diminutive suffix indicated smallness or youth — a *kitoun* was simply a small cat.
The Anglo-Norman form *kitoun* derived from Old French *chitoun*, which used the diminutive suffix *-oun* (from Latin *-ōnem*). The base word *chat* descends from Late Latin *cattus*, the word that gave most of Western Europe its common term for the domestic cat: French *chat*, Spanish *gato*, Italian *gatto*, German *Katze*, English *cat*.
When *kitoun* entered English, it gradually adapted to native phonetic patterns. The French ending *-oun* shifted to *-en*, matching the pattern of English words like *maiden*, *chicken*, and *oxen*. By the 15th century, *kitten* had settled into its modern form.
## What It Replaced
Before *kitten* arrived, Middle English used *catling* — a native diminutive formed from *cat* plus the suffix *-ling*. The imported French word proved more durable, perhaps because it sounded more distinct from its base word. *Catling* survived for a time as a word for catgut strings on a musical instrument but eventually faded.
## The Verb
By the 1400s, English speakers had turned the noun into a verb: *to kitten* meant for a cat to give birth. This animal-specific birthing verb follows a pattern: cows *calve*, horses *foal*, dogs *whelp*, cats *kitten*. The verb remains in use, though it is less common in everyday speech than the noun.
## Idioms and Extensions
*Kitty*, the informal diminutive of *kitten*, appeared by the early 18th century. The phrase *having kittens* — meaning to be extremely agitated or anxious — is first attested in the 19th century. Its origin may be humorous exaggeration (as if one's distress were as dramatic as a cat in labor), though folk etymologies connect it to medieval beliefs about witchcraft and pregnancy.
*Sex kitten*, dating from the late 1950s, applied the word's connotations of playfulness and softness to human attractiveness. The word *kitten* has accumulated metaphorical uses almost entirely centered on smallness, youth, and a certain endearing vulnerability.
## The Afroasiatic Root
The deep origin of *kitten* — like that of *cat* itself — probably lies outside the Indo-European family. Late Latin *cattus* appeared alongside the spread of the domesticated cat from North Africa and the Near East. Cognates in Afroasiatic languages (Nubian *kadīs*, Berber *kaddîska*) suggest the word traveled with the animal. *Kitten* is thus a diminutive of a French word, from a Latin word, from a source that predates all of them.