noun
slight acidity; weakly acidic
Used to describe substances, solutions, or conditions that are mildly acidic, often in scientific, cosmetic, or everyday contexts.
この石鹸は弱酸性で肌に優しい。
This soap is slightly acidic and gentle on the skin.
弱酸性の溶液を調整する。
Prepare a weakly acidic solution.
強酸性 means 'strong acidity', the opposite end of the pH scale from 弱酸性.
Compound of 弱 (じゃく, 'weak') + 酸性 (さんせい, 'acidity').