the highest mountain in the world. Everest is in the Himalayas, on the border between Tibet and Nepal. It was first climbed in 1953 by Sir Edmund Hillary, from New Zealand, and Tenzing Norgay, from Nepal, who were members of a British team. People sometimes mention the name "Everest" when they are talking about an extremely difficult achievement.:
• Cancer researchers have made some progress, but they still have an Everest to climb.
Definition from the Longman Dictionary of Contemporary English Advanced Learner's Dictionary.