Chimera

Chimera (pronounced ki-meer-uh or kahy-meer-uh)

(1) A mythological, fire-breathing monster commonly represented with a lion's head, a goat's body, and a the tail of a dragon or serpent (often with initial capital).

(2) Any similarly grotesque monster having disparate parts, especially as depicted in decorative art.

(3) A horrible or unreal creature of the imagination.

(4) A vain or idle fancy.

(5) In biology, an organism (especially a cultivated plant) composed of two or more genetically distinct tissues, as an organism that is partly male and partly female, or an artificially produced individual having tissues of several species.

(6) In applied genetics, a slang term used by scientists describing one who has received a transplant of genetically and immunologically different tissue.

(7) In medicine, twins with two immunologically different types of red blood cells.

(8) In zoology, (using the alternative spelling chimaera) any of various cartilaginous fishes of the order Chimaeriformes.

1350-1400: From the Middle English chimera, from the Old French chimere, from the Medieval Latin chimera, from the Classical Latin chimaera, from the Ancient Greek Χίμαιρα (Khímaira or Chímaira) (she-goat).  Chimaera translates literally a "year-old she-goat", the masculine form being khimaros from kheima (winter season) from the primitive Indo-European gheim (winter) and related to the Latin hiems (winter), the Ancient Greek cheimṓn (winter), the Old Norse gymbr and the English gimmer (ewe-lamb of one year (ie one winter) old).  The alternative spelling chimaera is used always of the fish and sometimes of the mythological beast.

The chimaera, a mythical fire-breathing creature depicted often with a lion's head, a goat's body and the tail of a dragon or serpent, was one of the many fantastical offspring of Typhon and Echidna and a sibling of such monsters as Cerberus and the Lernaean Hydra.  In all of antiquity, sighting the chimeara was an omen of storms, shipwrecks, and natural disasters (particularly volcanoes).  It was depicted usually by (almost always male) writers as female and was killed by the hero Bellerophon in Lycea.  There arose the tradition that the chimaera was supposedly an ancient personification of snow or winter, but the connection to winter might be no more than the ancient habit of reckoning years as "winters" and maybe just another of the many quasi-mythological imaginings of Medieval writers.  It was in antiquity held to represent a volcano so perhaps the idea of a link to a symbol of "winter storms" (another sense of Greek kheima) and generally of destructive natural forces held some appeal. The word was used generically for "any grotesque monster formed from parts of other animals" which in the pre-modern world were frequently conjured up for any number of reasons.

The now extinct alternative spelling was chimeraor and the practice of using an initial capital (known from Latin) when describing the mythical monster is common although there’s no basis in the rules of English.  The most common modern use, the figurative meaning "wild fantasy" was known in thirteen century French and first recorded in English in the 1580s.

Bellerophon Riding Pegasus Fighting the Chimaera (1635) by Peter Paul Rubens (1577–1640).