Misnomer

A misnomer is a word or term that suggests a meaning that is known to be wrong. Misnomers often arise because the thing received its name long before its true nature was known, or because the nature of an earlier form is no longer the norm. A misnomer may also be simply a word that is used incorrectly or misleadingly. "Misnomer" does not mean "misunderstanding" or "popular misconception", and many misnomers remain in legitimate use (that is, being a misnomer does not always make a name incorrect).

Sources of misnomers

Some of the sources of misnomers are:

• An older name being retained after the thing named has changed (e.g. tin can, mince meat pie, steamroller, tin foil, clothes iron, digital darkroom). This is essentially a metaphorical extension with the older item standing for anything filling its role.
• Transference of a well-known product brand name into a genericized trademark (e.g., Xerox for photocopy, Kleenex for tissue or Jell-o for gelatin dessert).
• An older name being retained even in the face of newer information (e.g., Chinese checkers, Arabic numerals).
• Pars pro toto, or a name being applied to something which only covers part of a region. The name Holland is often used to refer to the Netherlands while it only designates a part of that country; sometimes people refer to the suburbs of a metropolis with the name of the biggest city in the metropolis.
• A name being based on a similarity in a particular aspect (e.g., "shooting stars" look like falling stars but are actually meteors).
• A difference between popular and technical meanings of a term. For example, a koala "bear" (see below) looks and acts much like a bear, but in actuality, it is quite distinct and unrelated. Similarly, fireflies fly like flies, and ladybugs look and act like bugs. Botanically, peanuts are not true nuts, even though they look and taste like nuts. The technical sense is often cited as the "correct" sense, but this is a matter of context.
• Ambiguity (e.g., a parkway is generally a road with park-like landscaping, not a place to park). Such a term may confuse those unfamiliar with the language, dialect and/or word.
• Association of a thing with a place other than one might assume. For example, Panama hats originate from Ecuador, but came to be associated with the building of the Panama Canal.
• Naming particular to the originator's world view.
• An unfamiliar name (generally foreign) or technical term being re-analyzed as something more familiar (see folk etymology).
• Anachronisms, terms being applied to things that belong to another time, especially much later.

Examples

Older name retained

• The "lead" in pencils is made of graphite and clay, not lead; graphite was originally believed to be lead ore, but this is now known not to be the case. The graphite and clay mix is known as plumbago, meaning "lead ore" in Latin, and is still known as "black lead" in Keswick, Cumbria and elsewhere.
• Blackboards can be black, green, red, blue, or brown. And the sticks of chalk are no longer made of chalk, but of gypsum.
• Tin foil is almost always actually aluminium, whereas "tin cans" made for the storage of food products are made from steel with a thin tin plating. In both cases, tin was the original metal.
• Telephone numbers are usually referred to as being "dialed" although rotary phones are now rare.
• When a computer program is electronically transferred from disk to memory, this is referred to as loading the program. "Load" is a holdover term from the mid-20th century, when programs were created on punched cards and then loaded into a hopper for automated processing.
• In golf, the clubs commonly referred to as woods are usually made of metal. The club heads for "woods" were formerly made predominantly of wood.

Similarity of appearance

• Catgut is made from sheep intestines.
• The English horn is neither English in origin nor a horn.
• Head cheese is actually a meat product.
• A horned toad is actually a lizard.
• A velvet ant is actually a wasp.

Difference between common and technical meanings

• Koala "bears" are marsupials not closely related to the bear family, Ursidae. The name "koala" is preferred in Australia, where koalas are native, but the term "koala bear" is still in use today outside of Australia.
• Jellyfish and starfish are not even closely related to fish (although jellyfish do have a gelatinous structure similar to jelly).
• A peanut is not a true nut in the botanical sense, but rather a legume. Similarly, a coconut is not a true botanical nut but a fruit.
• Several fruit that are not true berries include strawberries, bayberries, raspberries, and blackberries.

Association with place other than one might assume

• Arabic numerals originated in India, though they came to be associated with the Arabs, who adopted them and introduced them to Europeans.
• The guinea pig (Cavia porcellus) originated in the Andes not Guinea, and additionally is a rodent and unrelated to pigs.
• French horns originated in Germany, not France.
• Chinese checkers did not originate in China, nor in any part of Asia.

Other

• Although dry cleaning does not involve water, it does involve the use of liquid solvents.
• The "funny bone" is not a bone—the phrase refers to the ulnar nerve.
• A quantum leap is properly an instantaneous change which may be either large or small. In physics, it is the smallest possible change that is of particular interest. In common usage, however, the term is often taken to mean a large, abrupt change.
• "Tennis elbow" (formally lateral epicondylitis) does not necessarily result from playing tennis, nor as a result of any other repetitive strain injury.