The phrase "a diligent reader" is correct and usable in written English.
You can use it to describe someone who reads carefully and attentively, often implying a strong commitment to understanding the material.
Example: "As a diligent reader, she always takes notes and highlights important passages in her books."
Alternatives: "an attentive reader" or "a thorough reader."
Even a diligent map reader must play detective to stay on top of it.
Fortunately, there are safe alternatives out there for the guy who grooms, but I'm not gonna lie: You'll have to become a diligent label reader to find them.
In place of what Kelly condescendingly called "the politics of do-good ism," the First Lady moved, over time, to a more effortful and less expansive persona — the diligent reader of the briefing book.
There are surprises in store for the diligent reader of this masterful introduction to recursion as a fundamental tool for expressing and solving problems.
Finding athletes who have gone the other way is far trickier, but diligent reader James Andrews managed to dig one up.
The diligent reader will have worked through several substantial examples, including systems that perform symbolic algebra, natural deduction, resolution, qualitative reasoning, planning, diagnosis, scene analysis, and temporal reasoning.
Perhaps three or four pages in the diligent reader will understand what the driver does not, but nonetheless Kipling pulls off the great feat of the ghost story, which is to haunt the reader no less than its characters.
The diligent reader can also learn, in excruciating detail, what time Pavlov took each meal during summer holidays (dinner at precisely 12 30 P.M., tea at four, and supper at eight), how many cups of tea he typically consumed each afternoon (between six and ten), and where the roses were planted in his garden ("around the spruce tree on the west side of the veranda").
