What does the word vigilant mean?

Usage examples for vigilant

  1. Frank, solicitous for the little fellow's safety, kept vigilant watch over him for some days, but no violence was attempted. – Frank's Campaign or the Farm and the Camp by Horatio Alger, Jr.
  2. But the vigilant Anastasia saw something which encouraged her. – The Green Flag by Arthur Conan Doyle
  3. I have been no less vigilant than Ragobah, yet I have failed, even as he has failed. – The-Darrow-Enigma by Severy, Melvin Linwood