clench in WordNet English dictionary

1. the act of grasping
   "he released his clasp on my arm"; "he has a strong grip for an old man"; "she kept a firm hold on the railing"
   clasp  clench  clutch  clutches  grasp  grip  hold 
   
2. a small slip noose made with seizing
   clinch  clench 
   

1. hold in a tight grasp
   "clench a steering wheel"
   clench  clinch 
   
2. squeeze together tightly
   "clench one's jaw"
   clench