off guard

/ɔfˈɡɑrd/
adjective
  1. Not ready or prepared for something unexpected; caught by surprise.
    • She was off-guard when her friend threw a surprise party for her birthday.
    • The sudden question caught me off-guard, and I didn't know how to answer.
    • The security guard was off-guard for a moment, and the thief slipped past him.
Antonyms
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