Any homoacetogenic bacterium

(music) A meter with three subdivisions for every pulse.

(Britain, slang) An overcomplicated task, especially one perceived as a waste of time. / (typically in the phrase 'in a faff') A state of confused or frantic activity.

(botany, zoology) Of a side that is facing away from the axis or central line, such as the underside of a leaf; or the back of an animal.