Thingamajig

Placeholder names are words that can refer to things or people whose names do not exist, are temporarily forgotten, are not relevant to the salient point at hand, are to avoid stigmatization, are unknowable/unpredictable in the context in which they are being discussed, or are otherwise de-emphasized whenever the speaker or writer is unable to, or chooses not to, specify precisely.

Placeholder names for people are often terms referring to an average person or a predicted persona of a typical user.

Linguistic role

These placeholders typically function grammatically as nouns and can be used for people (e.g. '' John Doe, Jane Doe''), objects (e.g. '' widget''), locations ("Main Street"), or places (e.g. ''Anytown, USA''). They share a property with pronouns, because their referents must be supplied by context; but, unlike a pronoun, they may be used with no referent—the important part of the communication is not the thing nominally referred to by the placeholder, but the context in which the placeholder occurs.

In their ''Dictionary of American Slang'' (1960), Stuart Berg Flexner and Harold Wentworth use the term ''kadigan'' for placeholder words. They define "kadigan" as a synonym for ''thingamajig''. The term may have originated with Willard R. Espy, though others, such as David Annis, also used it (or ''cadigans'') in their writing. Its etymology is obscure—Flexner and Wentworth related it to the generic word ''gin'' for engine (as in the ''cotton gin''). It may also relate to the Irish surname ''Cadigan''.

Hypernyms (words for generic categories; e.g., "flower" for tulips and roses) may also be used in this function of a placeholder, but they are not considered to be kadigans.

Examples

Placeholder words exist in a highly informal register of the English language. In formal speech and writing, words like ''accessory'', ''paraphernalia'', '' artifact'', '' instrument'', or '' utensil'' are preferred; these words serve substantially the same function, but differ in connotation.

Most of these words can be documented in at least the 19th century. Edgar Allan Poe wrote a short story entitled "The Literary Life of Thingum Bob, Esq.", showing that particular form to be in familiar use in the United States in the 1840s. In Gilbert and Sullivan's ''The Mikado'', W. S. Gilbert makes the Lord High Executioner sing of a "little list" which includes:

... apologetic statesmen of a compromising kind,

Such as: What d'ye call him: Thing'em-bob, and likewise: Never-mind,

and 'St: 'st: 'st: and What's-his-name, and also You-know-who:

The task of filling up the blanks I'd rather leave to you.

Some fields have their own specific placeholder terminology. For example, " widget" in economics, engineering and electronics, or "Blackacre" and "John Doe" or "Jane Doe" in law. "X-ray" was originally a placeholder name for an unexplained phenomenon.

Companies and organizations

* "Ace" and "Acme" were popular in company names as positioning words in alphabetical directories. They were generic, laudatory of whatever products they were used to promote and appeared at the beginning of most alpha-sorted lists. ("Acme" is a regular English word from the Ancient Greek , meaning summit, highest point, extremity or peak, and thus sometimes used for "best".) A well-known example of "Acme" as a placeholder name is the Acme Corporation whose products are often seen in the Wile E. Coyote and the Road Runner cartoons.
* "Mom and Pop" (in the United States) are occasional placeholders for the individual owners of a generic small family-owned business
* High Street (UK) or Main Street (US) for the business district of a small town or village, often contrasted as a commercial business entity against Threadneedle Street, City of London in the UK or Wall Street, New York City in America.
* "Advent corporation" is a term used by lawyers to describe an as yet unnamed corporation, while legal incorporation documents are being prepared. In the case of Advent Corporation, founder Henry Kloss decided to adopt this placeholder name as the formal legal name of his new company.
* "NewCo" or "Newco" is used in a similar way in the UK for an as-yet-unnamed company.
* Fictional brands such as Morley are often used in television and cinema as placeholders to avoid unintended product placement. "Brand X" has been used in television advertisements as a generic brand representing any other brand than the one being advertised.
* "XYZ Widget Company" has long been used in business and economics textbooks as a sample company. Also used as engraving text example on items such as plaques, trophy plates, etc. Occasionally appears on customizable promotional materials including stationery templates, business cards, advertising signage, cups, backpacks, and other "swag" samples.
* "Contoso" and previously "Northwind" are used as fictional businesses in Microsoft's training materials and documentation.
* "Oceanic Airlines" is used as a fictional airline in several films, TV programmes, and comic books, typically when it is involved in a disaster or another event with which actual airlines would prefer not to be associated.
* "Octan" is used by The Lego Group as a fictional oil company. Before 1992, they used real life oil companies Shell Oil, Exxon and Esso.

Computing

Placeholder names are commonly used in computing:
* Foo, Bar, Baz, and Qux (and combinations thereof) are commonly used as placeholders for file, function and variable names. Foo and bar are derived from foobar.
* Hacker slang includes a number of placeholders, such as ''frob