1. mĕsŏchŏrus — Lewis & Short
mĕsŏchŏrus, i, m., = meso/xoros,
I one who stands in the middle of a chorus (of dancers or singers) to lead it, a chorusleader (post-class.):
cum mesochorus dedit signum,Plin. Ep. 2, 14, 7; Sid. Ep. 1, 2; Schol. Juv. 11, 172.