Sentence:  I lean'd back in my Chair, and <WSD>overlook'd</WSD> what he was doing.—But, as if the young Rogue had had Eyes in his Elbows, he broke off what he had begun, and writ, thus, in a new Place.—"If an impertinent Old Fellow, that sits by me, did not <WSD>overlook</WSD> what I am writing, I should have told you a pleasant Secret—" 
Meaning of the word marked with <WSD> tags:  To observe or watch (someone or something) surreptitiously or secretly.