Uncatalysed

Part of speech: adjective

Definitions

1. Describing a chemical reaction that proceeds without the help of a substance that speeds it up, so it occurs more slowly on its own
2. Not speeded along by any catalyst, meaning the process runs at its natural rate with no added agent to promote it
3. Lacking a catalyst, so that a reaction or change takes place without the extra agent that would otherwise accelerate it

Etymology: "Uncatalysed" is a plain formation: the prefix "un-", meaning "not", attached to "catalysed," the British spelling of "catalyzed." The prefix descends from Old English "un-," which goes back to the same negating element found across the Germanic languages, and it has been productive in English for centuries. Attaching "un-" to a past-participle adjective like "catalysed" produces a description of something that has not undergone catalysis. "Catalysed" itself is the more interesting half. The verb is built on "catalysis," a term coined from Greek roots meaning roughly "dissolving down," and it was applied in chemistry to substances that speed a reaction without being consumed by it. The word therefore describes a reaction that proceeds without the helping agent, which is precisely what the prefix negates. Because "uncatalysed" is a technical adjective formed on demand, its usefulness lies in chemistry and biochemistry, where researchers compare reactions run with and without a catalyst. Its meaning is transparent from its parts, so no further history is needed.

Antonyms: catalysed