vigilant
\ VIJ-uh-luhnt \ , adjective;
1.keenly watchful to detect danger; wary: a vigilant sentry.
2.ever awake and alert; sleeplessly watchful.
Quotes:
She would have to remain vigilant : yes, vigilant against herself, vigilant against her own mind and the tricks it played!
-- Stavros Stavros, "The Sentimentalist," 2010
But no one ever dreams of being sober and vigilant at the right time, so the organization, like many larger such, is a broken reed.
-- Hugh Stowell Scott, "The Sowers," 1896
Origin:
Vigilant has been around in English since the 1400s. It comes from the Latin vigilāre meaning "to be watchful."
