WordNet
adj. not prepared or vigilant; "the blow caught him napping"; "caught in an off-guard moment"; "found him off his guard" [syn: napping, off-guard(a), off guard(p), off one's guard(p), off his guard, off her guard]
Usage examples of "off your guard".
We are not likely again to find so many circumstances agreeing to favour us, a dismantled house, yourself travelling alone and off your guard in a country with which you are unfamiliar and where none know you, and just outside the window a convenient pool.
But they know -- Bentley told us this -- that we come across here now and again, so I suppose they figured you'd be less off your guard with us.
Either of them could have killed you, caught off your guard as you were.
If devils exist, their first aim is to give you an anesthetic-to put you off your guard.
I mean a certain irritability which has sometimes thrown you off your guard.
Trying to get you off your guard, same trick worked with Archibald .
They may believe that you intend to strike next in some other spot entirely and that this is intended to put you off your guard and relax while they close in on where they fondly imagine you are, or they may not be bluffing and this may be intended to restrict your movements.
The way he gave out to be this Child cove, just to get you off your guard.