Meaning of Alertness
Unknown / অজানা / अज्ञात
fully aware and attentive; wide-awake; keen: an alert mind.
swift; agile; nimble.
an attitude of vigilance, readiness, or caution, as before an expected attack.
a warning or alarm of an impending military attack, a storm, etc.: We'd just boarded the bus when the alert sounded.
the period during which such a warning or alarm is in effect.