mesobrachys

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

mĕsŏbrăchys, m., = μεσόβραχυς (sc. pes),

a poetical foot of five syllables, of which only the middle one is short (e. g. pulcherrĭmarum; opp. to mesomacros), Diom. p. 479 P.