open secret

noun

something supposedly secret but actually known quite generally.

Origin

1875-80

Examples from the web for open secret

While their purpose was a kind of open secret then, their contributions were still largely unknown to the public.
It was an open secret that illegal miners enjoyed political cover bought with illicit donations.
Several key informants referred in elliptical ways to this phenomenon, so it may be an open secret.

British Dictionary definitions for open secret

open secret

noun

something that is supposed to be secret but is widely known

Idioms and Phrases with open secret

open secret

Something that is supposedly clandestine but is in fact widely known, as in It's an open secret that both their children are adopted. This expression originated as the title of a Spanish play by Calderón, El Secreto a Voces (“The Noisy Secret”), which was translated by Carlo Gozzi into Italian as Il pubblico secreto (1769). In English the term came into general use during the 1800s.