The phonological word or prosodic word (also called pword, PrWd; symbolised as ω) is a constituent in the phonological hierarchy. It is higher than the syllable and the foot but lower than intonational phrase and the phonological phrase. It is largely held to be a prosodic domain in which phonological features within the same lexeme may spread from one morph to another, from one clitic to a clitic host, or from one clitic host to a clitic. The phonological word and grammatical word are non-isomorphic. Sometimes what counts as a word for the phonology can be either smaller or larger than what counts as a word for syntactic purposes. A clear case of this mismatch is compound words, which count as two words phonologically, but one in the syntax.