Definition

1. Adjective Phrase:
   • Vigilant, cautious, and prepared for danger or difficulty: The phrase describes a state of being watchful and alert to potential threats, problems, or deception. It implies a defensive or careful stance.

Usage

• The phrase functions as a predicate adjective, typically following a linking verb like "be," "remain," or "keep."
• It is often used with the preposition "against" to specify the source of the potential threat.
• It describes a temporary state of heightened awareness prompted by a specific situation, rather than a permanent personality trait.

Examples

• Adjective Phrase:
  • After the recent security breach, all employees must be upon their guard.
  • She advised her friend to remain upon her guard against misleading advertisements.
  • The warning put the entire neighborhood upon its guard.

Advanced Usage

• "to be upon one's guard": To be in a state of alertness.
  • A good detective is always upon his guard.
• "to put/set someone upon their guard": To warn someone, causing them to become cautious.
  • The strange noise put me upon my guard.
• "to keep upon one's guard": To maintain a state of caution.
  • When traveling alone, it's wise to keep upon your guard.

Variants and Related Words

• On one's guard: This is a more common modern variant with identical meaning and usage.
  • Be on your guard for pickpockets in the crowd.
• Guard (n/v): The core word meaning to watch over, protect, or defend.
• Guarded (adj): Cautious and having reservations, often in speech or demeanor.
  • He gave a guarded response to the question.

Synonyms

• Alert: Quick to notice and respond to potential danger.
• Watchful: Carefully observing everything around.
• Vigilant: Keeping careful watch for possible danger or difficulties.
• Wary: Feeling or showing caution about possible dangers or problems.

Related Phrases

• On the alert: Ready and watchful for something.
• On the lookout: Actively searching or watching for something.
• Keeping one's eyes peeled: Being very watchful and observant.

Adjective

1. vigilant
   • on guard against con artists
   • must remain on your guard in such a situation