seasoned 老練 - To render competent through trial and experience

seasoned 老練 - To render competent through trial and experience

1. To improve or enhance the flavor of (food) by adding salt, spices, herbs, or other flavorings.
2. To add zest, piquancy, or interest to: seasoned the lecture with jokes.
3. To treat or dry (lumber, for example) until ready for use; cure.
4. To render competent through trial and experience: a lawyer who had been seasoned by years in the trial courts.
5. To accustom or inure; harden: troops who had been seasoned in combat. See Synonyms at harden.
6. To moderate; temper.

It is simultaneously a simple, easy-to-use language that has broad appeal, and a complex and nuanced collection of language mechanics which without careful study will elude true understanding even for the most seasoned of JavaScript developers.

Reference:

https://github.com/getify/You-Dont-Know-JS/blob/master/preface.md