nucleus (n.)

A term used by some INTONATION analysts, particularly those working within the British tradition, to refer to the SYLLABLE in a TONE UNIT which carries maximal PROMINENCE, usually due to a major PITCH change. The nuclear syllable (sometimes represented as N) is also referred to as the TONIC syllable. In GENERATIVE PHONOLOGY, the analogous notion is nuclear stress, with the relevant STRESS-ASSIGNMENT RULE referred to as the Nuclear Stress Rule (NSR). In the normal, unemphatic version of the sentence The lady saw the dog, the last word is nuclear, and will carry one of the possible nuclear tones in English. The nuclear tone is the most prominent pitch movement in a tone unit. In English, analyses of nuclear tones vary, but most recognize such contrasts as FALLING (transcribed with ` above or before the SYLLABLE in question), RISING ´, rising-falling ˆ, falling-rising ˇ and level ¯. Others are possible, including distinctions within these types, such as ‘high’ v. ‘low’ fall.

In GRAMMAR and SEMANTICS, the term is sometimes used to refer to the essential SUBJECT–PREDICATE or NP–VP STRUCTURE of a simple SENTENCE. Nuclear predications play a central role in FUNCTIONAL GRAMMAR.

In PHONOLOGY, the sub-CONSTITUENT of the syllable RHYME consisting of the HEAD of the syllable and any on- and OFF-GLIDES.