Noun
A sign, mark, or symbol.
(history) A medieval tower bell used particularly for ringing the 8 canonical hours.
Synonym: signum bell
(mathematics) A function that extracts the sign of a real number x, yielding -1 if x is negative, +1 if x is positive, or 0 if x is zero.
Synonyms: signum function, sign function
He was standard-bearer for the centurial signum, a spear shaft decorated with medallions and topped with an open hand to signify loyalty, which was a rallying point for the soldiers. Source: Internet
Each legion, furthermore, had a vexillifer who carried a vexillum or signum, with the legion name and emblem depicted on it, unique to the legion. Source: Internet
Non-examples Plot of the signum function. Source: Internet
The wearing of signet rings (from Latin "signum" meaning sign) goes back to ancient Egypt; the distinctive personal signature was not developed in antiquity and most documents needed a seal. Source: Internet