Final answer:
Winston cannot claim he visited O'Brien for the dictionary as it would not be believable; it highlights the surveillance and control in '1984'.
Step-by-step explanation:
In 1984 by George Orwell, Winston cannot use the excuse that he has come for the dictionary because it would not be a believable or sufficient reason for him to be at O'Brien's place.
The oppressive society in which he lives is vigilant against any signs of unorthodox behavior or thought. Any excuse for visiting another individual is subject to scrutiny, and the simplistic reasoning for obtaining a dictionary does not hold enough merit to justify the interaction under the watchful eyes of Big Brother.
The scene underscores the theme of surveillance and the lack of personal freedom in the novel's dystopian setting.