What does aniline mean?
Aniline is an oily, colorless organic liquid — formally an aromatic amine with the formula C6H5NH2 — that darkens on exposure to air and light. First isolated in the nineteenth century from indigo and later obtained in bulk from coal tar, it became one of the foundational substances of the modern chemical industry. Its chief importance lies not in any use in its own right but in its role as a building block: aniline is the precursor for a vast range of products, including synthetic dyes, rubber-processing chemicals, herbicides, photographic developers, and especially polyurethane foams. The word also survives in phrases such as 'aniline dye' and 'aniline leather', referring to coloring agents and finishes descended from those early discoveries. Though largely invisible to the public, aniline is hazardous — it is toxic if inhaled, swallowed, or absorbed through the skin — so it is handled strictly under industrial safety protocols. For anyone interested in chemistry or industrial history, aniline marks the point where dyestuffs moved from plants to laboratories.
nounAniline is a colorless to slightly yellow, oily, toxic organic compound (C6H5NH2) derived from benzene, used chiefly as a starting material in the manufacture of dyes, drugs, plastics, and photographic chemicals.
- The chemical compound C6H5NH2, an aromatic amine used as an industrial precursor to dyes, pharmaceuticals, polyurethanes, and other products.
- A class or shade of synthetic dyes made from this compound, as in 'aniline dyes' or 'aniline colors'.
"The chemist distilled aniline from the coal tar and watched it darken slowly as it oxidized in the air."
"Most flexible polyurethane foam is made using aniline as a key starting material."
"The antique chair had been stained with an aniline dye that gave the leather its rich, translucent color."
Rarely pluralized; the plural appears mainly in technical discussions of substituted aniline compounds (e.g., substituted anilines).
"The study compared the reactivity of several substituted anilines."
In 1856, an eighteen-year-old student trying to synthesize quinine accidentally created the world's first synthetic dye from aniline — and launched the entire modern chemical industry.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of aniline
The word aniline was coined in the 1840s, when the Russian-German chemist Nikolai Fritsche isolated the compound from indigo dye and named it after 'anil', the Portuguese term for the indigo plant, which itself traces back through Arabic to Sanskrit. The suffix '-ine' marked it as a chemical substance, following the naming conventions of the day. After Perkin's accidental synthesis of mauveine from aniline in 1856, the word became firmly embedded in the vocabulary of the booming synthetic dye industry.
How aniline is actually used
Aniline is primarily a technical term encountered in chemistry, industry, and the history of science rather than everyday conversation. In industrial contexts it is often referred to simply as aminobenzene or phenylamine. Because pure aniline is highly toxic and readily absorbed through the skin, references to it often carry connotations of industrial hazard.
Easily confused with aniline
Anil is the indigo plant (and the Portuguese name for indigo dye) from which 'aniline' was originally derived, whereas aniline is the synthetic chemical compound itself.