Tough guy going round concealing dread (8)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

ANGST (in Existentialist philosophy, this is the dread caused by the awareness that your future is not determined but must be freely chosen) in REG reversed. Personally, I’d be far more dreadful if I thought my future wasn’t freely chosen. Which, I suppose, means I’d never make much of an Existentialist.  Hands up who thought the definition was ‘tough guy’ and couldn’t parse it?