(also formal poly·graph ) noun
a piece of equipment that is used, for example by the police, to find out if sb is telling the truth
(also formal poly·graph ) noun
a piece of equipment that is used, for example by the police, to find out if sb is telling the truth
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005