Domain

usgb/dəʊˈmeɪn/Volume
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LampPro Tip 1/2
Expertise IndicatorPlay
Use 'domain' to refer to someone's area of expertise or specialized knowledge within a certain area. SlideShe'll handle the negotiations; that's her domain.
LampPro Tip 2/2
Not PhysicalPlay
'Domain' often describes conceptual areas rather than physical spaces when talking about knowledge or activities. SlideQuantum mechanics is outside my domain of understanding.