1. (a.) Not aware; not noticing; giving no heed; thoughtless; inattentive.

2. (adv.) Unawares.

a stranger to aback asleep blind to caught napping dead to deaf to heedless ignorant impercipient in ignorance of incognizant inexpectant inobservant insensible insensible to lost to mindless napping nonconceiving nonexpectant not with it oblivious out of it short sudden suddenly unacquainted unadmonished unadvised unanticipatedly unanticipating unanticipative unaware of unconscious unconscious of unenlightened unexpectedly unexpecting unfamiliar unforewarned unguessing unhearing uninformed uninsightful uninstructed unknowing unmindful unmindful of unperceiving unprehensive unprepared unready unrealizing unseeing unsuspecting unwarned unwitting witless