off guard

The Shooting guard (SG), also known as the two or off guard, is one of five traditional positions on a basketball team. Players of the position are often shorter, leaner, and quicker than forwards. A shooting guard's main objective is to score points for their team. Some teams ask their shooting guards to bring up the ball as well; these players are known colloquially as "combo guards". A player who can switch between playing shooting guard and small forward is known as a swingman.
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Adjective
1. not prepared or vigilant; "the blow caught him napping"; "caught in an off-guard moment"; "found him off his guard"
(synonym) napping, off-guard(a), off guard(p), off one's guard(p), off his guard, off her guard, off your guard
(similar) unready

Adjective
1. not prepared or vigilant; "the blow caught him napping"; "caught in an off-guard moment"; "found him off his guard"
(synonym) napping, off-guard(a), off guard(p), off one's guard(p), off his guard, off her guard, off your guard
(similar) unready

not alert to the unexpected It caught me off guard when she suddenly asked me to lend her $800.

Synonyms and related words:
asleep, culpably negligent, derelict, goofing off, inadvertent, inattentive, incautious, laissez-faire, lax, loose, napping, neglectful, neglecting, negligent, nodding, noninterfering, nonrestrictive, overly permissive, permissive, procrastinating, relaxed, remiss, scamping, skimping, slack, sleeping, slighting, slurring, unalert, uncautious, uncircumspect, unguarded, unprepared, unready, unrigorous, unvigilant, unwary, unwatchful
  

NON IN GUARDIA