realm Meaning, Definition & Usage

  1. noun a domain in which something is dominant
    kingdom; land.
    • the untroubled kingdom of reason
    • a land of make-believe
    • the rise of the realm of cotton in the south
  2. noun the domain ruled by a king or queen
    kingdom.
  3. noun a knowledge domain that you are interested in or are communicating about
    region.
    • it was a limited realm of discourse
    • here we enter the region of opinion
    • the realm of the occult

WordNet

Realm noun
Etymology
OE. realme, ream, reaume, OF. reialme, roialme, F. royaume, fr. (assumed) LL. regalimen, from L. regalis royal. See Regal.
Definitions
  1. A royal jurisdiction or domain; a region which is under the dominion of a king; a kingdom.
    The absolute master of realms on which the sun perpetually alone. Motley.
  2. Hence, in general, province; region; country; domain; department; division; as, the realm of fancy.

Webster 1913