watchfully

/ˈwɑtʃfəli/
adverb
  1. In a way that pays close attention to what is happening, especially to avoid danger or mistakes.
    • The guard watched watchfully for any sign of trouble.
    • She walked watchfully through the dark alley, listening for footsteps.
    • The cat sat watchfully by the mouse hole, waiting for movement.
Antonyms