To ruin completely; spoil: The ancient manuscripts were destroyed by fire. To tear down or break up; demolish. See Synonyms at ruin. To do away with; put an end to: "In crowded populations, poverty destroys the possibility of cleanliness\u201d ( George Bernard Shaw). To kill: destroy a rabid dog. To subdue or defeat completely; crush: The rebel forces were destroyed in battle. To render useless or ineffective: destroyed the testimony of the prosecution's chief witness. To be destructive; cause destruction: "Too much money destroys as surely as too little\u201d ( John Simon).