The most common and most likely answer to this crossword clue is the 4 letter word READ
I've seen this crossword clue in The Guardian
R
E
A
D
More clues leading to the result READ
- Register money being in short supply
- Not fully prepared to study
- Study religious education, leading to a first in divinity
- Almost prepared to study
- Study concerning the current time?
- Announce info extracted from computer?
- Nearly prepared to deliver
- Learn from a book: note, a hardback
- Understand most of game
- Studied colour on the radio
Buddy explains!

The straight part
We know that "Learn from a book" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case learn from a book = read.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does READ mean?
READ noun- A reading or an act of reading, especially an actor's part of a play.
- (in combination) Something to be read; a written work.
- A person's interpretation or impression of something.
- An instance of reading.
- To look at and interpret letters or other information that is written.
- To speak aloud words or other information that is written. Often construed with a to phrase or an indirect object.
- To read work(s) written by (a named author).
- To interpret, or infer a meaning, significance, thought, intention, etc. from.
- To consist of certain text.
- Of text, etc., to be interpreted or read in a particular way.
- To substitute (a corrected piece of text in place of an erroneous one); used to introduce an emendation of a text.
- (usually ironic) Used after a euphemism to introduce the intended, more blunt meaning of a term.
- To be able to hear what another person is saying over a radio connection.
- To observe and comprehend (a displayed signal)
- (except Scotland) To make a special study of, as by perusing textbooks.
- To fetch data from (a storage medium, etc.).
- To think, believe; to consider (that).
- To advise; to counsel. See rede.
- To tell; to declare; to recite.
- To recognise (someone) as being transgender.
- To call attention to the flaws of (someone) in either a playful, a taunting, or an insulting way.
- To look at and interpret letters or other information that is written.
- To speak aloud words or other information that is written. Often construed with a to phrase or an indirect object.
- To read work(s) written by (a named author).
- To interpret, or infer a meaning, significance, thought, intention, etc. from.
- To consist of certain text.
- Of text, etc., to be interpreted or read in a particular way.
- To substitute (a corrected piece of text in place of an erroneous one); used to introduce an emendation of a text.
- (usually ironic) Used after a euphemism to introduce the intended, more blunt meaning of a term.
- To be able to hear what another person is saying over a radio connection.
- To observe and comprehend (a displayed signal)
- (except Scotland) To make a special study of, as by perusing textbooks.
- To fetch data from (a storage medium, etc.).
- To think, believe; to consider (that).
- To advise; to counsel. See rede.
- To tell; to declare; to recite.
- To recognise (someone) as being transgender.
- To call attention to the flaws of (someone) in either a playful, a taunting, or an insulting way.