What is the meaning of Kingdom?

A realm having a king and/or queen as its actual or nominal sovereign.

A realm, region, or conceptual space where something is dominant.

A rank in the classification of organisms, below domain and above phylum; a taxon at that rank (e.g. the plant kingdom, the animal kingdom).

dominion, lordship, rulership

The dominion and authority of God

kingdom, monarchy

state, realm

tribe, clan

region, domain, zone

The region where a planet's influence predominates

Source: wiktionary.org