Where does this definition of shale oil come from?
This entry for shale oil is sourced from Main Dictionary, one of the dictionaries and corpora merged into Lughet.
Is shale oil a noun, verb, or something else?
In this entry, shale oil is tagged as 2n..
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.