生石灰|せいせっかいseisekkai[3]nakadaka (mid-high)

1. nounquick lime

• Synonym石灰せっかいNeutralA general term covering 「生石灰」, 「消石灰」 and the like; in everyday speech people just say 「石灰」, while 「生石灰」 means calcium oxide specifically.
• Related酸化カルシウムさんかカルシウムWrittenThe chemical name for the same substance, used in chemistry and academic writing; 「生石灰」 is the everyday and industrial term.
• Antonym消石灰しょうせっかいNeutralCalcium hydroxide made by adding water to 「生石灰」; milder in nature, used for things like improving soil.

In everyday speech, 「石灰」 is the loose general word. Use 「生石灰」 for calcium oxide itself, especially where its heat-generating reaction with water matters; 「酸化カルシウム」 is the chemical term, and 「消石灰」 is what forms after water is added.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 石灰石せっかいせきを熱ねっして作つくられる酸化さんかカルシウムの別称べっしょう。