Theta nigrum

'unlucky theta') is a symbol of death in Greek and Latin epigraphy.

[1] Isidore of Seville notes the letter was appended after the name of a deceased soldier and finds of papyri containing military records have confirmed this use.

The term theta nigrum was coined by Theodor Mommsen.

It consists of a circle with a diagonal line.

The theta signified Thanatos, the Greek deity of death.

Retiarius vs Secutor , the two gladiators lying are dead, as signified by the theta nigrum .