ap·po·si·tion / ˌapəˈzishən/ • n. 1. chiefly technical the positioning of things or the condition of being side by side or close together.2. Gram. a relationship between two or more words or phrases in which the two units are grammatically parallel and have the same referent (e.g., my friend Sue; the first U.S. President, George Washington).

APPOSITION. Two consecutive, juxtaposed NOUNS or noun phrases are in apposition when they refer to the same person or thing, and when either can be omitted without seriously changing the meaning or the grammar of a sentence. Mrs Thatcher and the British Prime Minister are in apposition in Mrs Thatcher, the British Prime Minister, became leader of the Tory party in 1975. Here, both Mrs Thatcher became leader … and The British Prime Minister became leader … could serve equally well alone. The term is often used when these criteria only partly apply, some grammarians using terms like partial or weak apposition to distinguish various types of lesser acceptability: ‘The heir to the throne arrived, Prince Charles’ (where only the second noun phrase can be omitted).

apposition The addition of layers of cellulose to the inner surface of a plant cell wall, at its junction with the plasma membrane. This type of growth results in thickening and strengthening the cell wall and usually occurs when elongation of the cell is complete. Compare intussusception.

apposition (apŏ-zish-ŏn) n. the state of two structures, such as parts of the body, being in close contact. For example, the fingers are brought into apposition when the fist is clenched.