Fetid

Definition

Having a strong, offensive, often decay-like or sulfurous odor; in entomology and arachnology, describes defensive secretions, pheromones, decomposing substrates, or carrion-associated species. Fetid odors frequently serve as chemical defenses against predators or as kairomones attracting carrion-feeding insects.

Etymology

From Latin fetidus, stinking; related to foetere, to stink.

Example

The defensive spray of the bombardier beetle (Brachinus spp.) releases a fetid, hot quinone mixture that repels predators; similarly, carrion beetles (Silphidae) locate fetid decaying vertebrate remains through olfactory cues.

Synonyms

• malodorous
• putrid
• foul-smelling

Related Terms

• olfaction
• chemical defense
• Kairomone
• carrion
• decomposition
• defensive secretion
• sebacic acid

Usage Notes

Distinguished from 'putrid' (specifically decaying organic matter) and 'rancid' (oxidized fats/oils). In taxonomy, 'fetidus/fetida/fetidum' appears in specific epithets (e.g., Eisenia fetida, the 'manure worm') referring to odoriferous habitats or defensive secretions. Not interchangeable with 'acrid,' which denotes sharp, irritating vapors rather than rotten smells.