What does acidic mean?
"Acidic" is an adjective describing something that has the properties of an acid, most precisely meaning a substance with a pH below 7 on the standard acidity scale. In chemistry, it applies to solutions, soils, and compounds: lemon juice, vinegar, and gastric fluid are all acidic, while soap and baking soda are not. The word also appears frequently in everyday contexts — gardeners speak of acidic soil favored by plants like blueberries and rhododendrons, and cooks describe acidic ingredients such as tomatoes or citrus that brighten a dish's flavor. By extension, "acidic" has developed a vivid figurative sense: an acidic remark or tone is one that is sharply critical, biting, or corrosive in effect, as when a reviewer delivers an acidic takedown of a film. This metaphorical use gives the word real expressive power beyond the laboratory. Derived from "acid," which traces back through Latin to the idea of sourness, "acidic" is a versatile term that bridges science, cuisine, and pointed language alike.
adjectiveHaving the properties of an acid; having a pH of less than 7. Also used figuratively to describe speech or writing that is sharply bitter or cutting.
- Having the chemical properties of an acid, or a pH below 7.
- (Of taste) sour or tart, like lemon juice or vinegar.
- (Figurative, of remarks or tone) sharply critical, biting, or harsh.
"The soil was too acidic for the hydrangeas, so she added lime to raise the pH."
"Rain in industrial regions can be mildly acidic, slowly eroding limestone buildings."
"Her review of the novel was so acidic that the author reportedly refused to read it."
Your stomach dissolves food using hydrochloric acid so strong it would burn your skin — yet its lining renews itself every few days just to survive being acidic.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acidic
"Acidic" derives from "acid," which entered English from French "acide," itself from Latin "acidus" meaning "sour, sharp-tasting," from the root "ac-" signifying sharpness or point. That same Latin root gave rise to related English words such as "acrid" and "acuity." The adjective "acidic" formed later, likely in the 19th century alongside the development of modern chemistry and the pH concept, extending the older noun into a general descriptive adjective.
Related word forms
How acidic is actually used
In scientific contexts (chemistry, soil science, medicine), "acidic" carries a precise technical meaning tied to pH. In everyday use it often describes sour flavors. The figurative sense — describing cutting or sarcastic commentary — is common in journalism and criticism and overlaps with "acerbic," though "acidic" tends to suggest sharper hostility.
Easily confused with acidic
"Acetic" refers specifically to acetic acid (the acid in vinegar), while "acidic" is the general adjective describing anything acid-like or having a low pH.
"Ascetic" describes a person practicing severe self-discipline and abstinence, whereas "acidic" relates to acids or sharp bitterness — the words merely sound similar.