Late 17th century: from Latin felinus, from feles 'cat'.

• cat from Old English:

  The original Latin word for cat was feles, literally ‘she who bears young’ and also used of other animals such as polecats that were domesticated to keep down mice. This is the source of our feline (late 17th century). In the early centuries ad cattus appears in Latin. It is generally thought to be Egyptian, as this is where cats were first domesticated, but a Slavic language is another possibility. Most modern European languages used a word derived from this. It is typical of the different roles played in English by words from Latin and Germanic sources that while feline is generally linked with positive words like ‘grace’, catty (late 19th century) is an insult. Catgut (late 16th century) is typically made from sheep not cats, and may come from a joke about the caterwauling (Late Middle English), from cat and a word related to ‘wail’, noise that can be produced from the strings. Cat features in many colourful English expressions. A cat may look at a king, meaning ‘even a person of low status or importance has rights’, is recorded from the mid 16th century. If you let the cat out of the bag you reveal a secret, especially carelessly or by mistake. The French have a similar use of ‘bag’ in the phrase vider le sac, literally ‘empty the bag’, meaning ‘tell the whole story’. When the cat's away the mice will play dates from the 15th century. To put the cat among the pigeons was first recorded in 1706, and appears then to have referred to a man causing a stir by surprising a group of women. No room to swing a cat probably refers not to the animal but to a cat-o'-nine-tails, a form of whip with nine knotted cords which was formerly used to flog wrongdoers, especially at sea. Something really good might be called the cat's whiskers, the cat's pyjamas or, in North America, the cat's miaou. Like the bee's knees, these expressions were first used in the era of the ‘flappers’, the 1920s. African-Americans started calling each other cats from the middle of the 19th century, a meaning that jazz musicians and fans took up. See also whisker.