Green’s Dictionary of Slang

reader n.

1. [18C–1900s] (UK Und.) a wallet or pocket-book.

2. [mid–late 18C] (UK Und.) a book.

3. [mid-19C+] (also luminous reader) a marked card; thus (gambling) readers, a crooked deck of cards that a cheat can read from the backs.

4. [1910s–40s] (US Und.) a permit, e.g. to beg, to street-sell.

5. [1930s] a newspaper.

6. [1930s] (US Und.) a small-time thief who follows postmen or delivery men to their destination, having sneaked a look at the label, then claims to be the official recipient.

7. [20C+] (US Und.) a warrant for arrest.

8. [1930s–50s] (UK Und.) a ‘wanted’ poster.

9. [1930s+] (drugs) a drug prescription; thus reader with a tail, an illegally issued prescription which had been traced by narcotics agents.

10. [1940s+] (UK prison) any form of reading matter, books, magazines, comics etc.

11. [1960s] a pornographic novel, without pictures.

In compounds

reader hunter (n.)

[early 19C] (UK Und.) a pickpocket specializing in stealing wallets and pocket-books.

reader merchant (n.) [merchant n.]

[late 18C–mid–19C] a pickpocket specializing in the theft of wallets and pocket-books.

In phrases

draw a reader (v.) (also nail a reader, nap a reader)

[late 18C–mid-19C] (UK Und.) to steal a pocketbook.