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

Be cautious when using vinegar, though, because its high acidity can break down the rubber seal and gaskets in your dishwasher over time. —Karen Brewer Grossman, Southern Living, 6 Dec. 2025

Experts say most people can enjoy it daily, but the acidity may bother sensitive stomachs or damage tooth enamel. —Laura Schober, Health, 4 Dec. 2025

The acidity of coffee varies too much to reliably predict its effect on potting soil. —Leanne Potts, Better Homes & Gardens, 3 Dec. 2025

Your mouth is also home to other bacteria that compete with cavity-causing bacteria for resources and space, fighting them off and restoring the acidity of your mouth to levels that aren’t harmful to teeth. —Jacqueline Abranches, The Conversation, 2 Dec. 2025

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