Answer: watchful
Word Origin late 15th century: from Latin vigilant- 'keeping awake' from the verb vigilare from vigil (see vigil).
Scrabble Points: 12
Powered by Oxford Dictionaries
Kids Definition of vigilant : alert especially to avoid danger … he was constantly vigilant looking for the next nearest hiding place should the sound of engines come. — Lois Lowry The Giver
To be vigilant is to be watchful or alert for danger or some other kind of trouble. Vigilant can describe a person or an action. It is often used when talking about keeping something out or in—whether that means keeping mistakes out of your work robbers out of your home or the dog inside the house.
Some common synonyms of vigilant are alert watchful and wide-awake. While all these words mean "being on the lookout especially for danger or opportunity " vigilant suggests i...