essential/əˋsɛnʃəl; Iˈsenʃ$l/adj 1 important and necessary 重要的﹔必不可少的: +for/to A balanced diet is essential for good health. 均衡的饮食对于健康至关重要。It is essential that we make a decision soon. 我们必须马上作出决定。it is essential to do sth It is essential to book tickets early. 必须提早订票。2 most important or basic 最重要的﹔最基本的: The essential difference between them is their size. 他们最根本的区别是大小不同。see box at见 IMPORTANTand 和 NECESSARY 方框