密度高、拿起來沉的金屬
字面的一格：真的在講重量，也真的在講金屬。
noun · B2
A metal with a high density, such as lead, mercury or gold. Many heavy metals are poisonous, and they can build up in water, soil, food and the body.
重金屬（金屬元素）
核心畫面
Hold a small piece of lead in your hand. It is not big, but it is far heavier than it looks, and it lands with a dull thud when you put it down. That surprising weight is what the word heavy is doing here. Everything else the expression is used for keeps some part of that feeling: something with more weight in it than its size would suggest.
可以想成手裡握著一小塊鉛。它體積不大，但比看起來重得多，放下去的時候是「咚」的一聲悶響。heavy 在這個詞裡講的就…更多收起
可以想成手裡握著一小塊鉛。它體積不大，但比看起來重得多，放下去的時候是「咚」的一聲悶響。heavy 在這個詞裡講的就是那種重量。這個詞後來用在哪裡，多少都還留著這個感覺：分量比外表看起來更重。From the word’s history
The packet's etymology note says that, according to the Oxford World's Classics edition of Anthony Trollope's Rachel Ray (1863), heavy metal meant big guns, as on a warship. It also states plainly that the origin of the music sense is disputed: William S. Burroughs used the phrase in his fiction, and several critics (Sandy Pearlman, Lester Bangs, Mike Saunders) have each claimed to have coined it.
來源的字源註記說：依 Anthony Trollope《Rachel Ray》（1863）牛津版的註解，heavy metal 曾指軍艦上的大口徑火砲。同一段也直說音樂那個意思的來源有爭議：William S. Burroughs 在小說裡用過這個詞，Sandy Pearlman、Lester Bangs、Mike Saunders 幾位樂評也各自說是自己先用的。所以這裡只能記下有這些說法，不能替它選一個定論。
Wiktionary entry 'heavy metal' (etymology_text; kaikki:3f6f69a190036ae4:1036899124:23023)
Two branches
聽起來很重的音樂
這一家的連結是「重」這個感覺，而不是金屬本身。要說明的是：這是一個好記的想法，不是歷史上的來源——來源本身就說音樂用法的出處有爭議。
noun · B1
A kind of very loud rock music with a hard, heavy beat, built on electric guitars played at high volume with a rough distorted sound, often with long guitar solos and powerful singing.
重金屬音樂
原始詞典資料5 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
heavy metalnoun/ˈhɛv.i ˌmɛt.əl/
- 1
sciencesAny metal that has a specific gravity greater than about 5, especially one, such as lead, that is poisonous and may be a hazard in the environment. (There are many different definitions of what counts as a heavy metal; see Heavy metals for a discussion.)
- 2
entertainmentlifestylemusicA genre descended from rock music, characterized by the use of emphatic drumbeats, highly amplified distortion, and overall loudness; often featuring extended instrumental solos and powerful vocals.
- 3
entertainmentlifestylemusicA genre descended from rock music, characterized by the use of emphatic drumbeats, highly amplified distortion, and overall loudness; often featuring extended instrumental solos and powerful vocals.
- 4
Guns or shot of large size.
- 5
Great influence or power.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。