-ine3 Also -in.
[French, from the Latin feminine form -ina.]
One group is of abstract nouns: discipline, doctrine, famine, medicine, rapine, routine. Other examples from the same source are concubine and urine. A few are diminutives: figurine.
Many are names of products, often derived from something they are supposed to resemble or imitate (nectarine, a type of peach whose flavour was thought to be like nectar) or from which they derive (caffeine, a compound found especially in tea and coffee, from French café; dentine, the bony tissue forming the bulk of a tooth, from Latin dens, dent-, tooth). The ending has been used with no clear system to name substances (
In systematic chemical naming, -ine is used for alkaloids and basic substances (aconitine, nicotine, strychnine). It is regarded as distinct from -in, which appears in the names of neutral substances, such as glycerides, glucosides, and colouring matters (albumin, casein, chitin, pepsin). This distinction is not always strictly observed. In some cases, the non-scientific spelling in -ine exists alongside the systematic name in -in (gelatine and gelatin; glycerine and glycerin); however, US usage often prefers the forms in -in. Vitamin, originally vitamine, is so spelled everywhere.
The ending -ine was used to name the halogens (fluorine, chlorine, bromine, iodine, astatine) and this spelling has been preserved; -ine is also used systematically to form the names of certain six-membered monocyclic compounds having a nitrogen atom in the ring, as in azine, the source of a group of dyestuffs.
See also -idine.