sphere, domain, area, orbit, field, arena -- (a particular environment or walk of life; "his social sphere is limited"; "it was a closed area of employment"; "he's out of my orbit")
domain, demesne, land -- (territory over which rule or control is exercised; "his domain extended into Europe"; "he made it the law of the land")
domain, domain of a function -- ((mathematics) the set of values of the independent variable for which a function is defined)
world, domain -- (people in general; especially a distinctive group of people with some shared interest; "the Western world")
(Sound)
