Earth is the descending secondary element, the counterpart of air.
Earth is the most dense and earth-bound element - the most solid and enduring of the elements. It anchors our foundation, being firm, structured, and stable.
In a spiritual context, earth represents knowledge, affinity with nature, and being rooted. In such a context earth is expressed through balanced unification of the first three chakras: the root chakra, the navel chakra, and the solar chakra.
In Jungian psychology, earth represents sensation.
In a mundane context, earth represents the natural world, material wealth and possessions, work, stability. In such a context, earth is expressed via the root chakra.
Earth tends towards negativity.