Crossword Genius

Tough nut to crack (5)

Ross

There are a few possibilities for this:

Which length description are you looking for?:

5

6

'tough nut to crack' is the definition.
(I've seen this in another clue)

This is all the clue.

(Other definitions for enigma that I've seen before include "Solution to mystery" , "Gamine being a bit of a puzzle" , "German military cipher machine" , "It's mysterious like gamine" , "WW2 code" .)

I've seen this clue in The New York Times and The Wall Street Journal.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.