What is "tautosyllabic"

a. (context linguistics English) Occurring in the same syllable.

Two or more phonemes ( segments) are tautosyllabic (with each other) if they occur in the same syllable. Take for instance the English word "cat". Since this word is monosyllabic, the three phonemes /k/, /æ/ and /t/ are tautosyllabic. They can also be described as sharing a 'tautosyllabic distribution'. However, in the French word "être" (meaning "to be", syllabified ê-tre), only the three last phones /t/ and /r/ are tautosyllabic, all members of the second syllable. (However, much of French usage involves single-syllable êtr or even êt) Phonemes which are not tautosyllabic are heterosyllabic. For example, in the English word "mustard", /m/ and /t/ are heterosyllabic, as they are members of different syllables.