English Reference

Word

acidity

Phoneticsacid·i·ty

US/əˈsɪdəti/

UK/æsˈɪdɪti/

Definitions

01chemical level

B2 · Upper Intermediate Uncountable noun Science Technical

n. the amount of acid in a substance, such as soil, water, or a chemical liquid.

n. the chemical state or quality of being acid, typically measured on the pH scale. Uncountable in its general sense; countable when referring to specific levels or instances.

“The gardener tested the soil's acidity to see if it was right for the roses.”

“High levels of ocean acidity can have devastating effects on coral reefs and other marine organisms that rely on calcium carbonate.”

Synonyms

pH levelsourness

Antonyms

alkalinity

02sour taste

B2 · Upper Intermediate Uncountable noun Cooking

n. a sharp, sour, or tart taste in food and drink, like in lemons or coffee.

n. the sharp, tart, or sour sensory quality of a foodstuff or beverage. Often used as a positive attribute in professional tasting contexts like coffee or wine.

“I like this white wine because it has a refreshing acidity.”

“The chef added a squeeze of lime to the dish to balance the richness of the coconut milk with a bit of acidity.”

Synonyms

tartnesssharpnesstang

Antonyms

sweetnessblandness

03stomach acid

B2 · Upper Intermediate Uncountable noun Medicine

n. too much acid in your stomach, which can cause a burning feeling.

n. a condition of excessive acid in the gastric secretions, often leading to discomfort or heartburn.

“Eating spicy food late at night often gives him painful acidity.”

“The patient was prescribed antacids to neutralise the excess acidity that was causing chronic indigestion.”

Synonyms

heartburnacid reflux

04bitterness in speech

C2 · Proficiency Uncountable noun Literary

n. a sharp, unkind, or bitter way of speaking or writing.

n. a caustic, biting, or bitter quality in expression or temperament. Figurative use.

“There was a hint of acidity in her voice when she mentioned her rival.”

“The critic's review was marked by an unexpected acidity that seemed more personal than professional.”

Synonyms

Real-World Examples

“The sweetness helps round out the acidity for a smooth cup.”
787 Coffee 20 Sept 2026
“When a coffee lacks acidity, it tastes flat, one-dimensional, and often sweet in a cloying way.”
dabov.us 2 Aug 2024
“Whether your aim when brewing is to highlight a coffee’s natural, juicy acidity or avoid nasty sour notes, the good news is that you can.”
Perfect Daily Grind 29 Apr 2018
“And in my experience as a barista, coffee drinkers are always looking for body, along with bright acidity and defined flavors).”
Perfect Daily Grind 20 Sept 2017

Etymology

From French acidité, from Latin aciditātem, accusative singular of aciditās (“sourness, acidity”), from acidus (“sour, acid”). Equivalent to acid + -ity.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
Frequency
Frequent
Level
B2 · Upper Intermediate
Updated

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