[f. ALERT a. + -NESS.] The quality of being alert; quickness in observing and acting; briskness, activity, nimbleness.
1714. Spectator, No. 566, ¶ 4. That Alertness … which is usually so visible among Gentlemen of the Army.
1748. Anson, Voy., II. vi. (ed. 4), 271. His alertness rendered it impossible to seize him.
1816. Miss Austen, Emma, III. ix. 333. The alertness of a mind which could neither be undecided nor dilatory.
1873. Buckle, Civiliz., III. v. 281. A certain alertness and vigour of understanding.
