Definition of: spasm

(spaz′əm) noun
1. Any sudden or convulsive action or effort, as of the body, mind, or nature, especially such a one as is abnormal or temporary.
2. Pathol. Any involuntary convulsive contraction of muscles: when manifested by alternate contractions and relaxations it is a clonic spasm; when persistent and steady, it is a tonic spasm. [<L spasma, spasmus <Gk. spasmos <spaein draw, pull]