let one's hair down


Also found in: Dictionary, Thesaurus, Medical, Encyclopedia.

let one's hair down

Also, let down one's hair. Drop one's reserve or inhibitions, behave casually or informally, as in Whenever the two sisters get together, they let their hair down and discuss all their problems . This expression alludes to the practice of women taking down their pinned-up long hair only in the privacy of the bedroom. [c. 1900]
See also: down, hair, let