The phrase "serial liar" refers to someone who tells lies repeatedly and consistently. It means that the person is not honest and cannot be trusted to tell the truth. Full definition
But that doesn't mean he be let off the hook for humanizing a well - documented xenophobic, racist, and misogynistic serial liar, which is exactly what he did on Thursday.» (businessinsider.com)
Put another way, this Prime Minister may well be, at least on progressive promises, one of Canada's most notorious serial liars, and we're not willing to take that sitting down. (medium.com)
Former FBI director James Comey slammed President Donald Trump as a serial liar who tells «baffling, unnecessary» falsehoods. (businessinsider.com)