Butenedioid

Part of speech: adjective, noun

Definitions

1. A chemical compound derived from butenedioic acid, the unsaturated dicarboxylic acid that exists as maleic and fumaric acid
2. A substance formed from butenedioic acid, a four-carbon unsaturated dicarboxylic acid with two carboxyl groups
3. Any chemical compound that comes from or is built upon the butenedioic acid structure, such as its salts and esters

Etymology: This is a chemist's coinage, built from the systematic naming of carbon compounds rather than from older everyday vocabulary. "Butane" names a four-carbon chain, and the ending "-ene" marks a double bond between two of those carbons, giving "butene." The prefix "di-" means two, and "-oic" marks a carboxylic acid group, so "butenedioic acid" describes a four-carbon chain with a double bond and two acid groups. The ending "-oid" comes from Greek "eidos," meaning "form" or "likeness." Attached to a chemical name, it likely marks a term for something of the parent compound's kind, so this word probably refers to a substance related to butenedioic acid. Its meaning follows directly from its parts, and it works as either a noun or an adjective.