wind down
Synonym discussion
Sense: phrasal verb/1
All four expressions describe moving from a state of tension or activity to a calmer state, but they differ in register and scope. 'Wind down' (the phrasal verb) and 'unwind' are the most common and neutral — both work in conversation and informal writing, though 'wind down' emphasises a gradual decrease in energy while 'unwind' suggests releasing mental tension like a coiled spring. 'Decompress' is more formal and specific: it compares the body to a pressure chamber, so it best suits contexts involving high-pressure work or stress ('after the court case, the lawyer needed time to decompress'). 'Chill out' is the most informal and casual, suitable only among friends ('chill out, the exam is over'). In writing, prefer 'wind down' or 'unwind'; in speech with close friends, 'chill out' is natural. Example: 'After the conference, the speakers wound down with drinks at the hotel bar, while the younger attendees went to a club to chill out.'
Etymology
The phrasal verb 'wind down' comes from the physical action of winding a spring mechanism, such as in a clock or music box. When you wind a device in the opposite direction — down — it gradually releases its stored energy and slows to a stop. By the early 19th century, English speakers had extended this mechanical image to any process that gradually loses momentum: a party winding down, a business winding down its operations, or a person winding down after a busy day.
First known use
1944
1944, in the meaning defined at transitive sense