Skeleton in the closet

A hidden secret or shameful past kept out of sight, lurking like a grim relic that could ruin a reputation if revealed.

From 19th-century Britain, possibly tied to doctors hiding illegal dissection skeletons-literally stashed-in closets, as anatomy laws tightened. William Thackeray's 1845 essay used it figuratively for family secrets, and by 1850s slang, it meant any disgrace. It reflects Victorian repression and gothic tales, growing into a metaphor for the unspeakable tucked away in polite society.