251. Lose one’s cool Lose one’s cool: get angry; lose one’s temper Tim: Look at the manager. He lost his cool arguing with the boss. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Author: sayinsei 英語の発音矯正と会話クラスを提供する新宿の語学学校. A language school in Shinjuku offering English classes View all posts by sayinsei