To take in and interpret what is held in a source. Reading is reconstruction; two readers do not receive the same thing.
Old English rædan (to advise, to counsel, to interpret, to read), from Proto-Germanic redan (to advise); the same root gives ready and, by way of a compound, the name Aethelred — to read was first to make sense of something for someone, closer to advising than to merely decoding marks.
To take in and interpret what a source holds. The root's counsel is still there under the surface: reading was never neutral decoding, and no two readers, advising themselves as they go, take in quite the same thing.