Definition of “tribrach:”
a form of meter containing three unaccented syllables. (short, short, short)
According to the current Wikipedia page on Tribrach, (as of June 29, 2013,) “the existence of the tribrach has been contested by some writers.”
However, according to the same Wikipedia entry, this statement itself has been contested.
Tribrach is an amateur (i.e. completely for-the-love-of-it) blog dedicated to making poetry & articles about poetry easily available to those who might not have time to seek them out themselves.