enigma

/əˈnɪɡmə/noun

A person or thing that is mysterious and very hard to understand or explain.

Example sentence

“Even after working with him for years, my quiet colleague remains an enigma to me.”

Churchill's 'a riddle wrapped in a mystery inside an enigma' keeps the word famous. Applied to a person it suggests fascinating unreadability.

Related words

enigmaticMysterious and difficult to interpret or figure out.enhanceTo make something better, stronger, or more valuable.enlightenTo shine light on something; to provide it with light.engulfTo swallow up or completely cover something.enlistTo sign someone up on an official list or roll; to join or recruit into a group, especially the military.engrossTo copy a document in large, clear, carefully formed lettering; to prepare its final official version.