the keyOur editors are putting together more complete content — check back in about 20 minutesthe key名詞 · 2形容詞 · 1the key — noun名詞1. a small piece of metal used to open a lock1.名詞釋義a small piece of metal used to open a lock例句I need to find my car key.2. something that is very important or essential2.名詞釋義something that is very important or essential例句Hard work is the key to success.the key — adjective形容詞1 解釋1. very important or essential1.形容詞釋義very important or essential例句She played a key role in the project.