(ˈ)trī|sēmik adjective
or tri·seme ˈtrīˌsēm
Etymology: trisemic from Greek trisēm os of three time units (from tri- three + -sēmos, from sēmeion unit of time, mark, sign, from sēma sign) + English -ic; triseme from Greek trisēmos — more at tri- , semantics
: consisting of or equal in duration to three morae
a trisemic syllable