noun

• (archaeology) A 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.
  "Most Celtic houses in Britain were simply constructed. They were generally round as in the remains of the house at Little Woodbury in Wiltshire, the wheelhouse at Jarlshof in Shetland, or the house on an unenclosed platform at Greenknowe in Berwickshire. [...] The roof of the Greenknowe house was conical. It had rafters fanning outwards from a high top, like the spokes of an umbrella. You can see why it is called a wheelhouse. The rafters were held at their lower ends on a horizontal ring of timber that rested on vertical posts with Y-shaped tops."
• (Canada, US, baseball, 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."
• (Canada, US, figuratively) A person's area of authority or expertise.
  "Horse viruses are in Pat’s wheelhouse."
• (Canada, US, figuratively) A set of skills necessitated by a situation.
  "Ever since I started taking antipsychotics, managing my mental health has been a whole different wheelhouse."