- Full of watch; vigilant; attentive; careful to observe
closely; observant; cautious; -- with of before the thing to be
regulated or guarded; as, to be watchful of one's behavior; and with
against before the thing to be avoided; as, to be watchful against the
growth of vicious habits.
Meaning of 'watchful' (Princeton's WordNet)
1 . watchful
[ a]
Meaning (1): - engaged in or accustomed to close observation
Example in sentence:
alert enough to spot the opportunity when it came;
caught by a couple of alert cops;
constantly alert and vigilant, like a sentinel on duty
2 . watchful
[ s]
Meaning (2): - experiencing or accompanied by sleeplessness