Okay kiddo, do you remember the time when you were celebrating Halloween and you dressed up as a ghost? You were not really a ghost, but you were somewhere in between being a human and a ghost, right?
Similarly, a liminal deity is a god or goddess who is in-between two states or two worlds. These liminal deities are gods and goddesses that are not associated with one specific place or activity but can cross over between different realms. For example, Hermes, the Greek god of commerce, thieves, and travelers, is a liminal deity because he moves between different realms, including the mortal realm, the underworld, and the divine realm.
Liminal deities are often associated with thresholds or borders, whether physical or metaphorical. They are neither here nor there, but rather in the middle or in transition. Think of them as a bridge or a gateway connecting two different places or worlds.
So, to sum it up, a liminal deity is like someone who is both a ghost and a human, or like a traveler who can move between different places, and they are usually associated with borders or transitions between states or realms.