enigma

Described by some as an “enigma”, Mrs Trump has preferred to be less public than her predecessors, giving fewer speeches both in the White House and on the campaign trail.

The scientist played a crucial role in the Allies' victory over Nazi Germany in World War Two by helping to crack codes and deciphering the infamous Enigma machine at Bletchley Park.

For all his hate, misogyny and political lies, I have to admit, I am fascinated by Vance and the enigma he is.

Away from politics, Salmond was something of an enigma.

But Columbus’s birthplace is the biggest enigma.