What does the word fastness mean?

Usage examples for fastness

  1. Bertie had been safe in his mountain fastness, until her ill- starred advertisement coaxed him within reach of the police Briareus. – At the Mercy of Tiberius by August Evans Wilson
  2. The Britons assailed them in this fastness, and so long as it was day, harassed them with arrows and quarrels, with ships and with barges. – Arthurian Chronicles: Roman de Brut by Wace
  3. Once in his mountain fastness, he was perfectly secure, as no Spanish army would trust itself in the rocky range. – Our War with Spain for Cuba's Freedom by Trumbull White