Meaning

noun a particular environment or walk of life

noun territory over which rule or control is exercised

noun (mathematics) the set of values of the independent variable for which a function is defined

originEtymology tree Proto-Indo-European *dem- Proto-Indo-European *-s Proto-Indo-European *dṓmder. Proto-Italic *domanos Latin dominus Proto-Indo-European *-yós Proto-Italic *-ios Old Latin -ios Latin -ius Latin -ium Latin dominiumder. Old French demainebor. Middle English demayne English domain From Middle English demayne, demain (“rule”), from Old French demeine, demaine, demeigne, domaine…

Etymology from Wiktionary, CC BY-SA 3.0