1. An open expanse of opportunity and chance.
2. Frontier spirit; adventure, desire to try something completely new in life.
3. Wholesomeness, recalling an innocent, simpler way of life.
4. The adjective “plain” is usually the reverse; not ordinary, lavish, lush and full of vibrancy.
For a young woman to dream of crossing a plain, denotes that she will be fortunately situated, if the grasses are green and luxuriant; if they are arid, or the grass is dead, she will have much discomfort and loneliness. See Prairie.