Endotoxin

Part of speech: noun

Definitions

1. A toxic byproduct generated by pathogens that elicits disease symptoms in hosts
2. A harmful substance released by certain bacteria that can provoke significant immune responses in the body
3. A poisonous component produced by specific bacteria that induces adverse physiological effects in a host organism

Etymology: Endotoxin is a compound built from two pieces with quite different histories. The "endo-" part comes from ancient Greek "éndon", meaning "within" or "inside", the same root behind words like "endoscope" and "endocrine". The "toxin" part traces back to "tóxon", the Greek word for a bow, because poisons were often used on arrows. Ancient Greek speakers formed "toxikón" from it, meaning poison for arrows, and Latin borrowed this as "toxicum". English later took "toxin" from that Latin root with a Latin-style suffix, so the word for an arrow's weapon became the general name for a biological poison. "Endotoxin" is a modern scientific coinage, formed by joining "endo-" to "toxin". The name describes where the poison is found: it is part of the bacterial cell itself, not a substance the bacterium secretes outward. Its meaning therefore hinges on the inside-outside contrast that "endo-" carries, set against the older sense of "toxin" as a secreted poison.