Chimera Definition: From Mythical Beast to Mixed DNA

Chimera definition in three senses

1. The myth. In ancient Greek stories, the Chimera was a fire-breathing female monster with the head of a lion, the body of a goat and a serpent or dragon for a tail. A hero on a winged horse killed it.
2. The impossible idea. By extension, a chimera is a hope, plan or fear that exists only in the mind. Calling a goal a chimera says it cannot be reached, however attractive it looks.
3. The biology term. A chimera is one organism made of cells that came from two or more different fertilized eggs, so parts of its body carry different DNA. Scientists also use the word for lab-made animals or plants that combine cells from two sources.

A related use is any mixed or patched-together thing: a building that blends three styles, or a product that tries to be a phone, a camera and a wallet at once.

From Greek goat to English noun

English picked the word up in the late 1300s for the mythical monster, through Old French and Latin from Greek khimaira. That Greek word also meant a young she-goat, which fits the goat body in the middle of the beast. The figurative sense of a wild fantasy appears in English from the 1580s; French had used it that way much earlier.

The adjective chimerical, meaning fanciful or impossible to carry out, followed in the 1600s. The genetic sense came much later, once biologists needed a name for animals and plants made of mixed tissue, and the old monster with its three different bodies was a natural choice.

Chimera in sentences

• For years the team chased the chimera of a product that would please every customer, and they shipped nothing.
• The vet explained that the kitten's two-toned face may mean it is a chimera, though only a genetic test can confirm it.
• Total job security is a chimera; even the safest roles change over time.
• In the museum, a carved chimera with a lion's mane guarded the doorway.
• Her plan to finish the degree, start a business and train for a marathon in one term sounded chimerical to her parents.

The biology meaning, made simple

Most bodies grow from a single fertilized egg, so every cell carries the same genetic recipe. In a chimera, two early embryos, or cells from two sources, have merged, and the body ends up as a patchwork. Some people learn they are chimeras only when a DNA test of one tissue does not match a test of another.

Note that a sharp color split can also have other causes, which is why vets talk about possibility rather than certainty. Researchers also make chimeras on purpose, such as plants grafted from two varieties, to study how cells behave.

How to use it in your own writing

Chimera is a countable noun: a chimera, two chimeras. It often follows verbs of pursuit: chase a chimera, pursue a chimera, prove a chimera. You can also say something remains a chimera when it never becomes real.

Use the adjective when you want to describe the idea itself: a chimerical scheme, chimerical hopes. In science writing, chimeric is the usual adjective: a chimeric protein, chimeric mice. The capital C is kept for the named monster of myth; the everyday senses use a small letter.

Close words and how they differ

The big difference from hybrid: a hybrid mule has the same mixed DNA in every cell, while a chimera has separate patches of each.

Where you will run into it

You will meet chimera in mythology classes, on old church roofs where stone beasts are sometimes given that name, in opinion columns that call a policy goal a chimera, and in science news about genetics and transplant research. It also sits comfortably beside other words for the strange and unreal, such as enigma, surreal and ethereal. Our everyday vocabulary hub gathers more words of this kind.