Desmethyl

Part of speech: noun, adjective

Definitions

1. A chemical compound or molecule from which one or more methyl groups have been removed or is lacking
2. Describing a substance that results from the loss or absence of a methyl group from a parent compound
3. A compound in which one or more of the original methyl substituents have been taken away or are not present

Etymology: "Desmethyl" is a chemist's construction, built from the prefix "des-" and "methyl." The prefix comes from Latin "dis-," meaning "apart" or "undoing," which reached English through Old French "des-" (as in "dessert" and "describe," where the sense is removal or reversal). The "methyl" part traces back to Ancient Greek "méthu," meaning "wine," joined with "hū́lē," meaning "wood" or "matter." Chemists formed "methyl" in the nineteenth century for the methyl group, which was first isolated from wood spirit, the alcohol obtained by distilling wood. Put together, "desmethyl" describes a compound from which a methyl group has been removed. Chemists use it constantly in pharmacology, where a drug's breakdown product is often named by adding "desmethyl" to the parent drug's name.