Paraldehyde

Part of speech: noun

Definitions

1. A sedative drug once used to induce sleep and calm agitation ; a cyclic compound formed when acetaldehyde molecules bond together in a ring
2. An older sleep-inducing medication that depresses the nervous system ; a ring-shaped chemical made by trimerizing acetaldehyde
3. A hypnotic sedative used to treat insomnia and restlessness ; an organic trimer produced from acetaldehyde in a six-membered ring structure

Etymology: Paraldehyde is a chemical compound, and its name is a coinage built from two parts. "Aldehyde" was formed in the 1800s by the German chemist Justus von Liebig, a shortening of "alcohol dehydrogenatum," reflecting that aldehydes were alcohol with hydrogen removed. The prefix "para-" comes from Greek "para," meaning "beside" or "alongside," and in chemistry it marks a polymer: paraldehyde is three aldehyde molecules joined into a ring, so the name means "the aldehyde polymer" in effect. The compound was first made in 1829 by the French chemist Justus Liebig's contemporary Jean-Baptiste Dumas, though the substance was originally described by others before its structure was understood. Its sedative effect was discovered later, and it came into medical use as a sleeping drug in the late 1800s, valued for a time as a cheaper alternative to chloral hydrate and other hypnotics.