acidity

noun

acid·​i·​ty ə-ˈsi-də-tē 

a-

plural acidities

1

: the quality, state, or degree of being acid

2

: the state of being excessively acid

Synonyms of acidity

• bitterness
• bite
• edge

Examples of acidity in a Sentence

detected a certain acidity in the way he responded

the acidity of their relationship was well known to their mutual acquaintances

Recent Examples on the Web

To successfully plant moss, prepare the soil properly, check for acidity, and diligently water the moss for the first few weeks until it is established. —Lauren Landers, Better Homes & Gardens, 9 Apr. 2026

Never use vinegar or citrus on marble or natural stone, as the acidity can damage the surface's finish. —Aliyah Rodriguez, The Spruce, 8 Apr. 2026

The acidity in brown sugar can work in tandem with baking soda to produce a nice rise, which white sugar alone can’t do. —Alana Al-Hatlani, Southern Living, 6 Apr. 2026

And like more tropical water corals, these ecosystems are also sensitive to changes in water temperature and acidity. —K. R. Callaway, Scientific American, 3 Apr. 2026

Word History

Etymology

borrowed from French & Late Latin; French acidité, going back to Middle French, borrowed from Late Latin aciditāt-, aciditās, from Latin acidus "sour, acid entry 2" + -itāt-, -itās -ity

First Known Use

1615, in the meaning defined at sense 1

Rhymes for acidity

• aridity
• avidity
• cupidity
• fluidity
• humidity
• liquidity
• lucidity
• morbidity
• placidity
• rancidity
• rapidity
• rigidity

Kids Definition

acidity

noun

acid·​i·​ty ə-ˈsid-ət-ē 

a-

plural acidities

1

: the quality, state, or degree of being acid

2

: the state of being extremely acid

Medical Definition

acidity

noun

acid·​i·​ty ə-ˈsid-ət-ē, a- 

plural acidities

1

: the quality, state, or degree of being sour or chemically acid

the acidity of lemon juice

2

: the quality or state of being excessively or abnormally acid : hyperacidity