ˈrelm, ˈreu̇m noun
( -s )
Etymology: Middle English realme, reaume, from Old French reialme, realme, reaume, modification (influenced by Old French reial royal, from Latin regalis ) of Latin regimen rule, government — more at regimen , royal
1. : kingdom
2.
a. : region , territory
seized power throughout the whole realm
b. : sphere , domain , range
within the realm of possibility
3. : any of several major biogeographic divisions: as
a. : a primary marine faunal division
b. : a primary terrestrial division consisting of one or more regions
c. : a division coordinate with a biogeographic region