What does carboxylic mean?
Carboxylic is an adjective used in chemistry to describe organic compounds that contain a carboxyl group, a combination of a carbonyl and a hydroxyl unit written as -COOH. This small molecular grouping is what makes organic acids acidic: it releases a hydrogen ion in solution, giving substances their characteristic sour taste and reactivity. The most familiar usage is the phrase 'carboxylic acid', the class name for compounds such as acetic acid (found in vinegar), citric acid (in citrus fruits), and fatty acids (components of fats and oils). The term derives from 'carboxyl', a nineteenth-century coinage blending 'carbon', 'oxygen', and the suffix '-yl'. Though rare outside scientific writing, the word underpins much of everyday life, from food chemistry to soaps, plastics, and pharmaceuticals.
adjectiveRelating to or containing a carboxyl group (-COOH), the characteristic functional group of organic acids such as acetic acid and citric acid.
- Of an organic compound: containing or characterized by a carboxyl group (-COOH), the functional group that gives organic acids their acidic properties.
"Vinegar owes its sharp taste to the carboxylic group in acetic acid."
"Citric acid is a tricarboxylic acid found in lemons and other citrus fruits."
"The reaction converts a primary alcohol into a carboxylic acid through oxidation."
The word 'carboxyl' is itself a chemical mash-up — coined in the 19th century by fusing 'carbon', 'oxygen', and 'yl', it names the very group that makes vinegar sour and soap slippery.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of carboxylic
The term derives from 'carboxyl', a combining form coined in the nineteenth century from 'carbo-' (Latin carbo, meaning coal or carbon), '-oxy-' (referring to oxygen), and '-yl', the standard suffix for univalent radicals. It thus literally describes a radical made of carbon and oxygen. English shares this construction with the international vocabulary of chemistry, and related terms such as 'carbonate' and 'carbohydrate' draw on the same Latin root for carbon.
Related word forms
How carboxylic is actually used
A technical term used almost exclusively in chemistry and biochemistry. It nearly always appears as a modifier before a noun, most commonly in the fixed phrase 'carboxylic acid'.
Easily confused with carboxylic
'Carbonic' relates to carbon dioxide and its acids (as in carbonic acid), whereas 'carboxylic' refers specifically to compounds containing the -COOH carboxyl group.