Definitions
1.nounA building or other structure containing a (large) wheel, such as the water wheel of a mill.
2.nounA prehistoric structure from the Iron Age found in Scotland, characteristically including an outer wall within which a circle of stone piers (resembling the spokes of a wheel) form the basis for lintel arches supporting corbelled roofing with a hearth at the hub.
3.noun(by extension from sense 1.2) A pitch location which is favourable to the hitter."The pitch was right in his wheelhouse, and he hit a grand slam."
4.nounA person's area of authority or expertise."Horse viruses are in Pat’s wheelhouse."