Angerona was an old Roman goddess of an unusual sort: a goddess of silence, whose statue showed her with her finger pressed to her lips and her mouth bound with a fillet, in token that she could not speak. Her festival, the Divalia or Angeronalia, was kept on the twenty-first of December, the winter solstice — the year's longest night, the moment of pause before the days lengthened — and this calendar position is suggestive: Angerona was the deity of the still moment, the dark turning, the held breath of the year.

She was credited by the priestly tradition with a great secret: she knew the secret name of Rome, the alternative name by which the city might be invoked, which was never spoken aloud and which, if spoken by an enemy and the proper rite performed, would call away the city's tutelary deities and leave it defenseless. This secret name — Angerona's name — was kept by the priesthood, and one priest alone in each generation was entrusted with it; even the consuls did not know. Pliny records that any man who pronounced the secret name would be put to death without trial, by ancient law.

The goddess was also invoked against angina, the choking-sickness, by sympathetic magic — silence and breathlessness being kindred — and her name was sometimes derived (rightly or not) from the verb angere, to choke. By the late Republic her festival had grown faint, but Macrobius records that it was still kept in his time, a rite for the pontifex maximus alone, performed at the altar of Vola Diva ("the goddess Vola") in the Sacrum Volupiae, on the slope of the Palatine.