stupefied, addled, befuddled, confused, muddled, bewildered, dumbfounded, dazed, stunned, dizzy, muzzy, groggy, foggy, fuzzy, vague, disorientated, disoriented, all at sea, mixed up, at a loss, at sixes and sevens
informal dopey, woozy, woolly-minded, discombobulated, fazed, not with it