or chiefly Brit  tran*quil*lize  or  tran*quil*lise  vt, -ized  or chiefly Brit  -lized  or  -lised  -iz*ing  or chiefly Brit  -liz*ing  or  -lis*ing  :  to make tranquil or calm : esp  :  to relieve of mental tension and anxiety by means of drugs tran*quil*iza*tion or chiefly Brit  tran*quil*li*za*tion  or  tran*quil*li*sa*tion  n 
 
 
 
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