alertness
US
UK alertness n: (awareness)
SC 警觉 jǐng jué
SC 机警 jǐng jué ，jī jǐng
Police caught the burglars red-handed thanks to the alertness of a neighbour.
mental alertness n: (clarity of mind, lucidity)
SC 警觉 jǐng jué
SC 警惕 jǐng jué ，jǐng tì
TC 警惕
TC 警惕
His mental alertness was impaired through lack of sleep.