[toc.sin] n [MF toquassen, fr. OProv tocasenh, fr. tocar to touch, ring a bell (fr. assumed VL toccare) + senh sign, bell, fr. ML & L signum; ML, bell, fr. LL, ringing of a bell, fr. L, mark, sign--more at touch, sign] (1586) 1: an alarm bell or the ringing of it
2: a warning signal