Noah Webster's 1828 American Dictionary of the English Language is regarded by many as the finest English
dictionary ever published. The dictionary is available in many forms. I made the content available here for my own purposes,
out of personal admiration for this particular dictionary.
ALERT', a. 1. Watchful; vigilant; active in vigilance. hence the military phrase, upon the alert, upon the watch, guarding against surprise or danger. 2. Brisk; nimble; moving the celerity.
alert appears in definitions for these words: AlertLeanyOn