Why is the ninth month called September?
c.1200, from Anglo-French conis, plural of conil "long-eared rabbit" (Lepus cunicula) from Latin cuniculus (source of Spanish conejo, Portuguese coelho, Italian coneglio), the small, Spanish variant of the Italian hare (Latin lepus), the word perhaps from Iberian Celtic (classical writers say it is Spanish).
Rabbit arose 14c. to mean the young of the species, but gradually pushed out the older word 19c., after British slang picked up coney as a punning synonym for cunny "cunt" (cf. connyfogle "to deceive in order to win a woman's sexual favors"). The word was in the King James Bible [Prov. xxx:26, etc.], however, so it couldn't be entirely dropped, and the solution was to change the pronunciation of the original short vowel (rhyming with honey, money) to rhyme with boney. In the Old Testament, the word translates Hebrew shaphan "rock-badger." Rabbits not being native to northern Europe, there was no Germanic or Celtic word for them.
(Heb. shaphan; i.e., "the hider"), an animal which inhabits the mountain gorges and the rocky districts of Arabia Petraea and the Holy Land. "The conies are but a feeble folk, yet make they their houses in the rocks" (Prov. 30:26; Ps. 104:18). They are gregarious, and "exceeding wise" (Prov. 30:24), and are described as chewing the cud (Lev. 11:5; Deut. 14:7). The animal intended by this name is known among naturalists as the Hyrax Syriacus. It is neither a ruminant nor a rodent, but is regarded as akin to the rhinoceros. When it is said to "chew the cud," the Hebrew word so used does not necessarily imply the possession of a ruminant stomach. "The lawgiver speaks according to appearances; and no one can watch the constant motion of the little creature's jaws, as it sits continually working its teeth, without recognizing the naturalness of the expression" (Tristram, Natural History of the Bible). It is about the size and color of a rabbit, though clumsier in structure, and without a tail. Its feet are not formed for digging, and therefore it has its home not in burrows but in the clefts of the rocks. "Coney" is an obsolete English word for "rabbit."