This is the 923rd most frequent Hungarian word.
béla
"Béla" is a Hungarian male given name.
Here, 'Béla' is used as a proper noun representing a male individual's name.
Béla elment a boltba.
Béla went to the store.
In this sentence, 'beli' is a suffix derived from 'béla', modifying 'könyv' to mean 'pertaining to the book'.
A könyv beli rajzok szépek.
The drawings in the book are beautiful.
Here, 'béla' is used idiomatically, as a slang term meaning something unpleasant or offbeat.