Compound

A compound is a word formed by combining two or more lexemes. Different word-classes (Noun, Adjective, or Verb) can be combined to form a compound, though the most productive type, as far as English is concerned, is the Noun+Noun compound. Compounds, in English and some other languages, can be written as one word or two separate words, and they can be hyphenated as well.

Compounds are often marked in ways that distinguish them from phrases. In English, for example, stress plays an important role in marking compounds. In the compound ‘greenhouse, stress falls on the first syllable, whereas in green 'house, an adjective modifying a noun, the stress falls on the second syllable.

Examples
The following are examples of English compounds:


 * football         (Noun + Noun)
 * babysit          (Noun + Verb)
 * pickpocket       (Verb + Noun)
 * snow-white       (Noun + Adjective)
 * dark-blue        (Adjective + Adjective)
 * brother-in-law   (Noun+ Preposition + Noun)

Subtypes
Compounds can be divided into the following patterns in terms of semantic headedness:

Endocentric compound, where one of the lexemes is considered the head of the compound and the other one as the modifier. Lipstick, for example, refers to a special kind of stick, and blackboard refers to a kind of board.

Exocentric compound, where the thing that the compound refers to isn`t the same as the head. A redhead for example isn`t a kind of head.

Coordinative compound, also known as copulative compound, where “the relation between members is like one of coordination: e.g actor-manager ΄ actor and manager΄”¹.

Appositional compound, where the parts of the compound refer to the same referent. A maidservant refers to a maid who is a servant.

Reference
Matthews, P. H. 2005. Oxford Concise Dictionary of Linguistics. Oxford: Oxford University Press.77.

Link
Utrecht Lexicon of Linguistics

Other languages
German Kompositum