What does the phrase 'and the stillness gave no token' mean in the poem 'The Raven'?

"Deep into that darkness peering, long I stood there wondering, fearing,

Doubting, dreaming dreams no mortal ever dared to dream before;

But the silence was unbroken, and the stillness gave no token,"

The narrator has just heard a tapping at his chamber door, but nothing was outside the door. The narrator is imagining the worst. The Word token here means 'clue' or 'tangible representation' for the source of the tapping.