From Longman Dictionary of Contemporary Englishblunt instrumentblunt instrumenta) a heavy object that is used to hit someone The victim suffered a blow to the head from a blunt instrument. b) a method of doing something that does not work very well because it has a lot of other effects that you do not want The exams are a blunt instrument that will reveal little about children’s abilities. → blunt
Examples from the Corpus
blunt instrument• After a while they kidnap and murder a young boy for kicks, bashing him over the head with a blunt instrument.• All the injuries were consistent with an enraged and merciless attack with a blunt instrument.• She looked around for a blunt instrument.• The cause of death had been the terrible bludgeoning he had received from a blunt instrument.• This is a very blunt instrument.• While the men exchanged blows the girl struck Farini from behind with a blunt instrument.• The blunt instrument obstinately refused to reveal itself and he doubted if there were any more revelations to be got out of anybody.• I sometimes think a blunt instrument would do some good for her. 