Origins of Some Cat Words and Phrases

Raining cats and dogs: 

Although sometimes small creatures such as fish and frogs might get sucked up into the sky by phenomena such as waterspouts and tornados, then fall from the sky over land, dogs and cats do not. Nor is it true that cats and dogs liked to sleep in the thatched roofs of Merry Old England, with the result that when it rained the tach became slippery and they fell out. 

The common explanation as to the origin of the phrase is that in 17th and 18th century England, heavy rains often caused flooding which brought with it, and left behind afterwards, the bodies of dead dogs and cats. 

The first recorded usage is in 1653 in Richard Brome's comedy The City Wit or The Woman Wears the Breeches. A reference to stormy weather uses the expression "It shall raine... Dogs and Polecats". Jonathon Swift used the modern format in 1738 in A Complete Collection of Polite and Ingenious Conversation: "I know Sir John will go, though he was sure it would rain cats and dogs". 

Cat got your tongue? 

Various origins have been suggested: 

• Sailors in the British navy were flogged with whips with multiple strands – a cat o’ nine tails – and that they went into a state of shock and silence after being flogged. 

• The Ancient Egyptians silenced blasphemers by cutting out their tongues and feeding them to cats. 

• That it comes from the medieval fear of witches and their familiars, black cats. 

However, the earliest use of the phrase is in an American magazine in 1881, where it is described as a taunt used by children, Ballou's Monthly Magazine, Volume 53: “Has the cat got your tongue, as the children say?” 

Cat o’ Nine Tails: 

The cat o' nine tails, commonly shortened to the cat, is a type of multi-tailed whip that originated as an implement for severe physical punishment, notably in the Royal Navy and Army of the United Kingdom, and also as a judicial punishment in Britain and some other countries, including Australia. 

The term first appears in 1681 in reports of a London murder. The term came into wider circulation in 1695 although the design is much older. It was probably so called in reference to its "claws", which inflict parallel wounds. 

There are equivalent terms in many languages, usually strictly translating, and also some analogous terms referring to a similar instrument's number of tails (cord or leather), such as the Dutch zevenstaart (seven tail[s]), negenstaart (nine tail[s]), the Spanish gato de nueve colas or the Italian gatto a nove code. 

Let the cat out of the bag: 

It has been suggested that if someone purchased a piglet at the markets in olden England, a cat was sometimes substituted for the piglet. Letting the cat out of the bag exposed the fraud and prevented purchase of a pig in a poke (bag). “Pigs in a poke” are recorded as early as 1530. 

The first documented use of the phrase in the sense of “revealing a secret" comes from a book review in a 1760 issue of The London Magazine, wherein the reviewer laments that, "We could have wished that the author had not let the cat out of the bag." 

Curiosity killed the cat: 

The original form of the proverb was "Care killed the cat", with care in this context meaning "worry" or "sorrow." 

The earliest printed reference to the original proverb is attributed to the British playwright Ben Jonson in his 1598 play, Every Man in His Humour, which was performed first by William Shakespeare: “...Helter skelter, hang sorrow, care will kill a cat, up-tails all, and a pox on the hangman.” 

Shakespeare used a similar quote in his 1599 play “Much Ado About Nothing: “What, courage man! what though care killed a cat, thou hast mettle enough in thee to kill care.” 

The origin of the modern variation is unknown. The earliest known printed reference to the actual phrase "Curiosity killed the cat" is in James Allan Mair's 1873 compendium A handbook of proverbs: English, Scottish, Irish, American, Shakesperean, and scriptural; and family mottoes, where it is listed as an Irish proverb. 

According to Phrasefinder: 

Curiosity hasn't received a good press over the centuries. Saint Augustine wrote in Confessions, AD 397, that, in the eons before creating heaven and earth, God "fashioned hell for the inquisitive". John Clarke, in Paroemiologia, 1639 suggested that "He that pryeth into every cloud may be struck with a thunderbolt". In Don Juan, Lord Byron called curiosity "that low vice". That bad opinion, and the fact that cats are notoriously inquisitive, led to the source of their demise being changed from 'care' to 'curiosity'.