: To stop someone from getting overly worked up or angry (e.g., "Cool your jets! It's not worth fighting over.").
If "cool your jets" feels too informal or dated, you might use: 1. Cool Your Jets
: One of its earliest recorded uses is in the 1952 novel Stand by for Mars! from the Tom Corbett, Space Cadet series, where a character is told, "Cool your jets, space creep!". : To stop someone from getting overly worked up or angry (e