Old English ræding, "a reading, the act of reading" either silent or aloud, "a passage or lesson," verbal noun; see read (v.)). Meaning "interpretation" is from mid-14c. (in reference to dreams). Meaning "a form of a passage of text" is from 1550s; that of "a public event featuring reading aloud" is from 1787.
county town of Berkshire, Old English Readingum (c.900), "(Settlement of) the family or followers of a man called *Read."