Compromised — a credential known to have appeared in a breach. A named security state rather than a concept.
Hacker and gaming slang from the late 1990s, generally traced to a typo of owned (the p and o sitting next to each other on a keyboard), fixed into the culture as its own spelling meaning thoroughly defeated or compromised; the exact first instance is disputed, but the typo-to-slang path is well attested.
Compromised, in the specific sense of a credential surfacing in a breach rather than merely guessed at. The typo the word began as is kept on purpose here: an accident of discovery becoming a fact worth taking seriously.