acidityPronunciation: /əˈsɪdɪti/Translate acidity | into German | into Italian Definition of acidity noun [mass noun] 1the level of acid in substances such as water, soil, or wine: the increased acidity of rainfall the level of acid in the gastric juices, typically when excessive and causing discomfort: smoking does not affect gastric acidity 2bitterness or sharpness in a person’s remarks or tone:the cutting acidity in his voiceacidity in other Oxford dictionaries Definition of acidity in the US English dictionary