Paradichlorobenzene

Part of speech: noun

Definitions

1. A chemical substance often utilized to repel moths and control odor in enclosed spaces
2. A solid organic compound commonly employed in mothballs to prevent insect damage and as a deodorizing agent
3. A crystalline chemical frequently used to keep clothes free from moths and to eliminate odors in storage areas

Etymology: Paradichlorobenzene is a chemical name built like a set of nested instructions. "Dichlorobenzene" describes a benzene ring carrying two chlorine atoms, and the prefix "para-" specifies that those chlorines sit on opposite sides of the ring, at positions 1 and 4. Chemists use "para-" this way for any ring substitution pattern, so the word is a systematic name rather than a common-language coinage. The compound itself is best known as the active ingredient in mothballs and room deodorizers, where it slowly sublimes from solid into vapour that repels moths and their larvae. The word therefore names a precise molecular arrangement, and its ordinary use is almost entirely in the chemical and consumer-product vocabulary rather than in everyday speech.