An abstract sphere of influence, real or imagined.

The domain of a certain abstraction.

(computing) A scope of operation in networking or security.

(formal or law) A territory or state, as ruled by a specific power, especially by a king.

(fantasy, roleplaying games) An otherworldly dimension or domain — magical, ethereal, or otherwise — usually ruled or created by a mystical character.

(virology, taxonomy) A taxonomic rank in the phylogeny of viruses, higher than kingdoms.