界 jiè
: boundary; scope; extent
: circles; group; domain
: kingdom (taxonomy)
Kun Reading
界 | さかい sakai
noun
: border; boundary
: area; region; spot; space; environment
: psychological state; mental state
On Reading
界 | かい kai
noun
: (biological) kingdom
: erathem (rock layer corresponding to the era in which it was deposited)
: partition of land
: (Suffix) the world of (some category)