boundless
Boundless is an idiom, the pronunciation is w ú Bi ā NW ú y á n, describing a wide range.
explain
The scope of description is very broad.
source
Xu Guangyao's fire in the plain: "they are in this village, in this boundless plain, swimming like fish."
usage
As a predicate, attributive, adverbial; as an adjective
boundless
an orphan-calf injures the nursing cow -- ingratitude - gū dú chù rǔ
Eating old things is like a stick in the neck - shí gǔ rú gěng