不可数名词：

1. 本质，实质，精髓

2. 香精，精油，精华液

英语解释

any substance possessing to a high degree the predominant properties of a plant or drug or other natural product from which it is extracted

the central meaning or theme of a speech or literary work

a toiletry that emits and diffuses a fragrant odor

the choicest or most essential or most vital part of some idea or experience