The trachea (windpipe) is to the spine as anterior.
In anatomical terminology, the term ‘anterior’ refers to a position that is toward the front of the body. The trachea is located in the front of the neck, while the spine runs along the back of the body. Therefore, saying the trachea is anterior to the spine indicates that the trachea is positioned in front of—or closer to the front of the body than—the spine.