Question: Is there a word or short phrase, which describes or implies the destruction of books or libraries?

Answer: 
The word you're looking for is **biblioclasm**.

According to [*Burning Books and Leveling Libraries: Extremist Violence and Cultural Destruction*](https://books.google.com.au/books?id=67CWswHay3QC&lpg=PA3&ots=NibyShqIKS&dq=oxford%20english%20dictionary%20%22biblioclasm%22&pg=PA3#v=onepage&q=oxford%20english%20dictionary%20%22biblioclasm%22&f=false), By Rebecca Knuth, it appears in the Oxford English Dictionary:

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> In the Oxford English Dictionary, *biblioclasm* is defined as "the breaking of books" and cited as first appearing in print in 1864 in a text on religious theory.
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After a bit or research I found it on the [Volume I (A-B)](https://archive.org/details/in.ernet.dli.2015.99992/page/n5) of the Oxford English Dictionary, published in 1913:

[![enter image description here](https://i.stack.imgur.com/R1smJ.png)](https://i.stack.imgur.com/R1smJ.png)

The quality is not good, but one can read:

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> **Biblioclasm** Destruction of books, or of the Bible. **Biblioclast**, a destroyer of books, or of the Bible. (Little more than nonce-words). **1864** T. Griffith *Plea Scripture* The Biblioclasm of the 'higher criticism' **1884** [illegible] Made bonfires of the Maya and Aztec manuscripts.. May these bishops expiate their crimes in the purgatory of biblioclasts.
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The etymology would be the famous noun βιβλίον (*little book*, or just *book*) and the less known verb κλάω (*to break*). It's worth mentioning that κλάω can also mean *to destroy*, which is a common meaning in biology, like in *osteoclast*.

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Note: If you want to coin a new word you can use *bibliopyrosis*, from πῦρ (*fire*). This seems to be completely new, since the [Google search](https://www.google.com/search?client=safari&rls=en&ei=C0YkXf2oOIfez7sP1aa-gAU&q=bibliopyrosis&oq=bibliopyrosis&gs_l=psy-ab.3...0.0..6017...0.0..0.0.0.......0......gws-wiz.SD6pX8eYadM) returns nothing.
Just to go in a different direction here: [bowdlerize](https://www.merriam-webster.com/dictionary/bowdlerize)
 to modify by abridging, simplifying, or distorting in style or content.