poly·graph 
/ˈpɑ:liˌgræf, Brit ˈpɒliˌgrɑ:f/ noun
plural poly·graphs /ˈpɑ:liˌgræf, Brit ˈpɒliˌgrɑ:f/ noun [count] 1 : lie detector
▪ They hooked him up to the polygraph and began the test. 2 US : a test that is done with a lie detector to see if someone is telling the truth
▪ She was asked to take a polygraph.
▪ They hooked him up to the polygraph and began the test.
▪ She was asked to take a polygraph.
