Aʿlam describes an animal with a natural cleft in the upper lip. Makhrūt denotes something pierced, and mārin the soft and flexible portion of the nose. The words refer to different features and should not be flattened into one anatomical label.
Here ʿatīq means excellent or well formed, not the legal status of a freed person. The verb tarjum describes a head-forward motion toward the ground, which the poet links to increased speed.