read
読 centers on the act of reading: visually interpreting written language to understand its meaning.
読 is the modern simplified form of 讀. The older form combines 言 (speech/words) with 賣, which likely contributed the sound and the idea of reading aloud or interpreting text. The modern right side 売 is a simplification.
The left side is 言 (words), and the right side 売 looks like a person with a book. Picture someone reading words aloud from a book.
For ドク, imagine a doctor reading a medical chart: doctor -> ドク, and the doctor reads the words carefully.
to read
reading
reader
reading (books)
Yomiuri (newspaper, etc. group)
buying and reading (book, magazine, etc.); subscribing (incl. free subscriptions); taking (e.g. newspaper)
pronunciation; reading (e.g. of a kanji)
reading aloud; recitation
deciphering; decoding
reading while standing (in a bookstore, etc.); browsing (i.e. reading an item but not buying it)
reading and writing
reading with pleasure
reading (e.g. by a scanner)
countdown
reading aloud
reading matter; reading material
must-read; required reading
to read out; to read aloud; to call out
to reread; to read again
reading-book; reader; guidebook; manual
on reading; on'yomi; Chinese-derived reading of a kanji
punctuation mark
kun reading; kun'yomi; native Japanese reading of a Chinese character
subscription (e.g. to a magazine)