Reading, so to speak, is a certain area (5)
I believe the answer is:
tract
'area' is the definition.
(tract is a kind of area)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for tract that I've seen before include "Stretch of land or religious pamphlet" , "Part of body" , "Region; pamphlet" , "Extended area of land" , "Large area of land or small booklet" .)