In linguistics, a disjunct is a type of adverbial adjunct that expresses information that is not considered essential to the sentence it appears in, but which is considered to be the speaker's or writer's attitude towards, or descriptive statement of, the propositional content of the sentence, "expressing, for example, the speaker's degree of truthfulness or his manner of speaking."[1]
A specific type of disjunct is the sentence adverb (or sentence adverbial), which modifies a sentence, or a clause within a sentence, to convey the mood, attitude or sentiments of the speaker, rather than an adverb modifying a verb, an adjective or another adverb within a sentence.
More generally, the term disjunct can be used to refer to any sentence element that is not fully integrated into the clausal structure of the sentence. Such elements usually appear peripherally (at the beginning or end of the sentence) and are set off from the rest of the sentence by a comma (in writing) and a pause (in speech).