Aldehyde

Part of speech: noun

Definitions

1. A family of organic compounds featuring a carbon atom with a double bond to oxygen and a single bond to hydrogen
2. Such substances are defined by a functional carbonyl group attached to a terminal hydrogen atom and play a role in various chemical processes
3. An organic molecule that includes a carbon-oxygen double bond connected to a carbon also bound to hydrogen, known as a formyl group

Etymology: The name "aldehyde" is a German contraction, built from the Latin words "alcohol" and "dehydrogenatum," meaning "dehydrogenated alcohol." The chemists who coined it were describing what happens when alcohol loses hydrogen: the molecule is stripped of two hydrogen atoms, leaving a carbon-oxygen double bond behind. The German form "Aldehyd" was then taken into English as "aldehyde." The Latin "alcohol" itself has a long and winding past. It traces back through medieval Latin to Arabic "kuḥl," a fine powder used as eyeliner, and before that to Aramaic and Akkadian words for a similar cosmetic substance. Chemists later applied the term to the volatile spirit distilled from wine, and the chain of meanings slowly shifted from a face paint to a chemical family.

Synonyms: carbonyl compound, formaldehyde, acetaldehyde, benzaldehyde, butyraldehyde