vigilance

noun3

1. •
   Alert watchfulness.

   • To-night she took her accustomed place; for, during the night, no vigilance could satisfy her but her own: any eye but hers might close in momentary forgetfulness. — 1837
2. •
   Close and continuous attention.

   • But you must remember, my fellow-citizens, that eternal vigilance by the people is the price of liberty, and that you must pay the price if you wish to secure the blessing. — 1837
3. •
   (no longer used) A guard; a person set to watch.