Knowing a subject deeply, and usually because you have spent time with it — read it, practised it, worked in it. It is not just 'has heard of'; someone well-versed in a topic can talk about the details and handle the awkward cases.

Knowing a subject deeply指對一個主題有深入的了解 and usually because you have spent time with it而且通常是因為花時間鑽研過 read it讀過 practised it練習過 worked in it在這個領域工作過 It它 is not just 'has heard of'不只是「聽過」而已 someone well-versed in a topic對某個主題 well-versed 的人 can talk about the details能談論細節 and handle the awkward cases也能處理棘手的狀況

It almost always comes with 'in': well-versed in tax law, well-versed in Taiwanese history, well-versed in the software. You can say it of practical skills too, not only book knowledge.

It它 almost always comes with 'in'幾乎總是跟 'in' 一起出現 well-versed in tax lawwell-versed in tax law（精通稅法） well-versed in Taiwanese historywell-versed in Taiwanese history（熟諳台灣歷史） well-versed in the softwarewell-versed in the software（熟悉這個軟體） You can say it你也可以用它來說 of practical skills too實作技能 not only book knowledge不只是書本上的知識

The word feels formal and respectful — you meet it in job ads, introductions, and news writing rather than in chat with friends. It is often used slightly loosely in job ads, where 'well-versed in Excel' may only mean 'can use it competently', so the strength of the claim depends on who is speaking.

The word這個詞 feels formal and respectful聽起來正式又帶著敬意 you meet it你會遇到它 in job ads, introductions, and news writing在徵才廣告、介紹和新聞寫作裡 rather than in chat with friends而不是在跟朋友聊天時 It它 is often used slightly loosely常常有點鬆散地被使用 in job ads在徵才廣告裡 where 'well-versed in Excel' may only mean「well-versed in Excel」可能只是指 'can use it competently'「能勝任地使用它」 so the strength of the claim所以這句話的份量 depends on who is speaking要看是誰在說

It works as a description after 'be' ('she is well-versed in...') and before a noun only rarely.

It它 works as a description可以作為描述 after 'be'放在 'be' 後面 ('she is well-versed in...')（「she is well-versed in...」） and before a noun only rarely但很少放在名詞前面