From the following words, it is obvious that the fourth meaning is the most appropriate:
Title: boundless
Pinyin: máng máng
Meaning:
1. Extensive and profound.
Ex.: The sky is grey, the fields are vast, and the wind blows the grass and the cattle and sheep are low.
Chapter 72 of Biography of Feng Ming Menglong in the Eastern Zhou Dynasty: "As for E-bamboo, overlooking the great river, there is no boat to cross. Before stopping the flood, the soldiers are in great danger after considering the pursuit. "
When the astronauts flying into space looked back at our earth, they found that the earth was a beautiful blue water polo in the vast universe.
2. Ambiguity. Example: The night is foggy.
3. lush. Example: Spring grass is boundless.
4. openness. Ex.: Under the sun, it is thousands of miles away, but it is not boundless. -Lao She's Grassland
Classification: words, reduplication.
Related verse: Ten years of life and death.
Under the sun, it is thousands of miles away, but it is not endless. (From Lao She's Grassland)