Volcanic is the adjective from volcano. Its first meaning is plain: belonging to a volcano, made by a volcano, or full of volcanoes — volcanic rock, volcanic ash, volcanic activity, a volcanic island, volcanic soil (which is famously rich, so farmers like it). Geography textbooks, news reports about eruptions, and travel writing about places like Iceland, Hawaii, Japan or Indonesia use it constantly.

Volcanic Volcanic is the adjective from volcano是volcano（火山）的形容詞。Its first meaning is plain它的第一個意思很簡單: belonging to a volcano屬於火山的, made by a volcano由火山造成的, or full of volcanoes或是充滿火山的 — volcanic rock像volcanic rock（火山岩）, volcanic ash volcanic ash（火山灰）, volcanic activity volcanic activity（火山活動）, a volcanic island a volcanic island（火山島）, volcanic soil volcanic soil（火山土） (which is famously rich, so farmers like it)（這種土出了名地肥沃，所以農夫喜歡）。Geography textbooks地理教科書, news reports about eruptions講火山爆發的新聞報導, and travel writing about places like Iceland, Hawaii, Japan or Indonesia以及寫冰島、夏威夷、日本或印尼這些地方的旅遊文章 use it constantly都經常用這個字。

It has a second, figurative use that students should notice: applied to people or feelings, it means sudden, huge, and hard to control — "a volcanic temper", "volcanic rage", "volcanic applause". The picture is of pressure building quietly and then bursting out all at once, so it suits anger better than gentle feelings; you would not call a soft sadness volcanic.

It有 a second, figurative use that students should notice第二個學生該注意的比喻用法: applied to people or feelings用在人或情緒上時, it means sudden, huge, and hard to control意思是突然、巨大、難以控制 — "a volcanic temper"像"a volcanic temper"（火山般的脾氣）, "volcanic rage""volcanic rage"（火山般的暴怒）, "volcanic applause""volcanic applause"（火山般熱烈的掌聲）。The picture這個畫面 is of pressure building quietly and then bursting out all at once是壓力靜靜累積、然後一次爆發出來, so it suits anger better than gentle feelings所以比較適合形容憤怒、不適合形容溫和的情緒; you would not call a soft sadness volcanic你不會把一種淡淡的哀傷叫做volcanic。

In careful writing there is a small difference worth knowing: volcanic covers everything to do with volcanoes, while geologists use volcanic rock in a narrow way for rock formed from lava that cooled at the surface, as opposed to rock that cooled deep underground. That fine distinction only matters in science class.

In careful writing在講究的文章裡 there is a small difference worth knowing有個小差異值得知道: volcanic covers everything to do with volcanoes volcanic涵蓋所有跟火山有關的東西, while geologists use volcanic rock in a narrow way而地質學家用volcanic rock時意思比較窄 for rock formed from lava that cooled at the surface專指岩漿在地表冷卻形成的岩石, as opposed to rock that cooled deep underground而不是在地底深處冷卻的岩石。That fine distinction這個細微的區別 only matters in science class只有在自然科學課上才重要。

Note that the adjective drops the o of volcano and adds -ic, so the stress moves: VOL-ca-no but vol-CAN-ic.

Note注意 that the adjective drops the o of volcano這個形容詞把volcano的o拿掉 and adds -ic再加上-ic, so the stress moves所以重音會移動: VOL-ca-noVOL-ca-no but vol-CAN-ic但vol-CAN-ic。