let one's hair down(redirected from let down one's hair)
let (one's) hair down
To cease acting formally or conservatively; to ignore or relinquish one's inhibitions or reservations. Also worded as "let down (one's) hair." Come on, Jim, this is a party! Let your hair down and go a little wild!
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]