ˈklōnəs noun
( -es )
Etymology: New Latin, from Greek klonos turmoil; akin to Latin celer swift — more at celerity
: a series of alternating contractions and partial relaxations of a muscle that in certain nervous diseases occurs in the form of convulsive spasms involving complex groups of muscles and is believed to result from alteration of the normal pattern of motor neuron discharge — compare tonus