Monocarboxylic

Part of speech: adjective

Definitions

1. Describing a chemical compound that has a single carboxyl group attached to its molecular structure
2. Referring to an organic molecule characterized by the presence of exactly one carboxyl functional group
3. Denoting a substance with only one carboxyl group as part of its chemical composition

Etymology: "Monocarboxylic" is a chemistry term describing a molecule that contains exactly one carboxyl group, the -COOH unit that gives carboxylic acids their acidity. It is a plain technical compound rather than a word with a dramatic backstory: its first half, "mono-", comes from Ancient Greek "monos", meaning "single" or "alone," and the same prefix appears in "monarch" and "monologue." Its second half, "carboxylic," was built in chemistry from "carboxyl," the name for the carbon-oxygen group in these acids. The Greek root has a long pedigree, tracing back to a very old Indo-European base for "alone," but the chemical use is a modern coinage. Chemists formed "carboxyl" by combining "carbon" with "oxygen" and the suffix "-yl," which marks a radical or group within a molecule. Adding "-ic" produced the adjective describing acids containing such a group, and the prefix "mono-" was then attached to specify a single group per molecule.