the Devil
n 1: (Judeo-Christian and Islamic religions) chief spirit of evil
and adversary of God; tempter of mankind; master of Hell
[syn: {Satan}, {Old Nick}, {Devil}, {Lucifer}, {Beelzebub},
{the Tempter}, {Prince of Darkness}]
2: something difficult or awkward to do or deal with; "it will
be the devil to solve"