Marion Cotillard would be spot on as the enigmatic French widow.
He was enigmatic, even to his friends, and he left a scant paper trail—Honest Abe was no confessional diarist.
But somehow this mischievous and enigmatic man had done just that.
1640s, from Late Latin aenigmaticus, from aenigmat-, stem of aenigma (see enigma). Enigmatical in the same sense is from 1570s. Related: Enigmatically.