what is spindle?
noun, plural: spindles. (1) A collection of minute fibers composed of microtubules, which are prominent during cell division, as mitotic spindle or mitotic apparatus''. (2) A specialized innervated muscle structure involved in the reflex action and in proprioception, as muscle spindle. (3) A species of a poisonous shrub or small tree of the genus Euonymus, originally used for making spindles used for spinning wool. (4) An EEG waveform that occurs during sleep, as sleep spindle.