Muscle spasm is a condition in which the muscles involuntarily contract, causing pain and discomfort. TWITCH is a term used to describe a sudden, brief, involuntary contraction of a muscle or group of muscles (6 letters). TIC is a term used to describe a sudden, repetitive, nonrhythmic motor movement or vocalization involving discrete muscle groups (3 letters). CRAMP is a term used to describe a painful, often involuntary, spasmodic contraction of a muscle (5 letters). CRICK is a term used to describe a sharp, localized pain caused by a muscle spasm (5 letters).