adjunct (n.)

A term used in GRAMMATICAL theory to refer to an optional or secondary element in a CONSTRUCTION: an adjunct may be removed without the STRUCTURAL identity of the rest of the construction being affected. The clearest examples at SENTENCE level are ADVERBIALS, e.g. John kicked the ball yesterday instead of John kicked the ball, but not *John kicked yesterday, etc.; but other elements have been classed as adjunctival, in various descriptions, such as VOCATIVES and ADJECTIVES. Many adjuncts can also be analysed as MODIFIERS, attached to the HEAD of a phrase (as with adjectives, and some adverbs). The term may be given a highly restricted sense, as when it is used in QUIRK GRAMMAR to refer to a subclass of adverbials. In X-BAR syntax, an adjunct is one of the major components of a phrasal category (the others being HEAD, COMPLEMENT and SPECIFIER).