heartland

Short definition from Wiktionary

Noun

1. 1
   Synonym of heart (“the seat of the affections or love”).
2. 2
   Also in the plural form heartlands: The interior part of a region, especially when contrasted with coastal parts or when regarded as particularly powerful or significant.
3. 3
   Also in the plural form heartlands: In the geopolitical theory of the English geographer Halford John Mackinder (1861–1947): the interior of the world island comprising north-central Eurasia regarded as politically powerful.
4. 4
   Also in the plural form heartlands: Residential districts and planning areas outside the city centre; the new towns of Singapore collectively.
5. 5
   Also in the plural form heartlands: The states in the centre of the United States, chiefly regarded as politically and socially conservative; also, the people living in such states collectively.
6. 6
   Also in the plural form heartlands: A region or part of a region particularly associated with or significant for a characteristic, such as an activity, a faith, support for a political party or other organization, etc.