wits

WITS noun

[ plural ] uk/wɪts/ us
intelligence and the ability to think quickly

сообразительность
 keep/have your wits about you
to be ready to think quickly in a situation and react to things that you are not expecting

быть начеку
You have to keep your wits about you when you're cycling. Идиомыbe at your wits ' endscare/frighten sb out of their wits