Definition of: spirochete

(spī′rə·kēt) noun
1. Any of a genus (Spirochaeta) of typically saprophytic bacteria commonly found in water and sewage, and characterized by spiral flexible filaments with apparently rotary movements. See illustration under BACTERIUM.
2. Any of various other similar micro–organisms of the order Spirochaetales, including those which cause syphilis and relapsing fever. Also spi′ro·chaete. [<Gk. speira coil + chaitē bristle]
—spi′ro·che′tal adjective