watch

verb (used without object)

1. to be alertly on the lookout, look attentively, or observe, as to see what comes, is done, or happens: to watch while an experiment is performed.
2. to look or wait attentively and expectantly (usually followed by for): to watch for a signal; to watch for an opportunity.
3. to be careful or cautious: Watch when you cross the street.
4. to keep awake, especially for a purpose; remain vigilant, as for protection or safekeeping: to watch with a sick person.
5. to keep vigil, as for devotional purposes.
6. to keep guard: She was assigned to watch at the door.