spasm spasm /ˈspæzəm/

noun

1. () A painful and involuntary muscular contraction  ( muscle spasm , cramp , spasm )
   a painful and involuntary muscular contraction
    I had a cramp in my leg while I was running, and it was very painful
   I had a cramp in my leg while I was running, and it was very painful
   
   
2. (pathology) sudden constriction of a hollow organ (as a blood vessel)  ( spasm )
   (pathology) sudden constriction of a hollow organ (as a blood vessel)