syllabary

n. A syllabary is a phonetic writing system whose symbols (graphemes) represent syllables or moras. A syllable is a rhythmic unit consisting of a cluster of segments inside a word, including an obligatory vowel (the nucleus) and optional consonants in onset (prenuclear) or coda (postnuclear) position. The Hiragana and Katakana writing systems used to write Japanese are syllabaries. – EMF