alertness
n. uncountable B2 Upper Intermediate US //əˈɫɝtnəs// UK //ɐlˈɜːtnəs// alert·ness
n. the state of being awake and ready to notice things. It means you are paying close attention to what is happening around you.
n. the state of being awake and mentally alert; the quality of being quick to notice or respond to something. Often used in medical or safety contexts to describe a person's level of consciousness.
The driver's alertness is very important on the highway.
The nurse monitored the patient's alertness to ensure the medication was not causing any drowsiness.
Maintaining high levels of alertness during the final hours of the shift requires a combination of physical stamina and mental discipline to avoid critical errors.
From alert + -ness.