Mora is a unit of sound used in phonology that determines stress in some languages. Like many technical linguistics terms, the exact definition of mora (plural moras or morae) is debated. The term, meaning "delay", comes from Latin.

In general, morae are formed as follows:

1. The first consonant of a syllable (the onset) plus the following vowel (the nucleus) plus the following consonant or cluster (the coda) represents one mora. Thus, the English word cat is unimoraic.
2. Consonants serving as syllable nuclei represent one mora. Thus, the Japanese word sensei teacher is quadrimoraic (se-n-se-i).
3. Long vowels count as two morae. Thus, the Abkhaz word k'ælaara hole is quadrimoraic (k'æ-la-a-ra).

Japanese is a language famous for its moraic qualities. Most dialects including the standard use morae as the basis of the sound system rather than syllables. ja:モーラ