Thioacetic

Part of speech: adjective

Definitions

1. Describing an acid in which a sulfur atom has replaced an oxygen atom, as in thioacetic acid used in organic chemistry
2. Relating to a sulfur-substituted analogue of acetic acid, a compound with a distinctive odor used in chemical synthesis
3. Characterizing a chemical compound derived from acetic acid in which sulfur takes the place of oxygen within its structure

Etymology: Thioacetic acid is named for the swap it makes. Its parent compound, acetic acid, is the sharp acid of vinegar, and "thio-" comes from the Greek "theion", meaning sulfur. In this compound, sulfur takes the place of one oxygen atom in the acid's structure. "Acetic" traces back to Latin "acetum", vinegar, from "acere", to be sour, which is also the root of English "acid". Chemists later attached "thio-" to existing names to describe compounds where sulfur replaces oxygen, so this is a systematic chemical coinage rather than an ancient word. The Greeks knew sulfur, but they had no name like this for it.