Where does this definition of on the books come from?
This entry for on the books is sourced from Main Dictionary, one of the dictionaries and corpora merged into Lughet.
Is on the books a noun, verb, or something else?
In this entry, on the books is tagged as 2adv..
What is Lughet?
Lughet is a free trilingual dictionary covering nearly five million entries across Uyghur, Chinese, and English, drawn from more than ten source dictionaries and corpora.