hyperalert

/ˌhaɪpərəˈlɜrt/
adjective
  1. Extremely watchful and aware; paying very close attention to possible dangers or changes.
    • New parents often become hyperalert to their baby's slightest cry or movement.
    • After the break-in, the family's dog remained hyperalert, barking at every small noise.
    • The security guard was hyperalert during the night shift, scanning the parking lot constantly.
Antonyms