motte and bailey

Noun

motte and bailey (plural mottes and baileys)

1. The predecessor of the European castle, having a raised earth mound (the motte) topped with a tower (or donjon), and a wooden ring fortification surrounding a courtyard (the bailey).
   • Should an inquiring stranger ask an Irish countryman if there were any "mottes" in the neighbourhood he might be met with unexpected but none the less unrestrained laughter, as in semi-slang the word has another meaning very far from that of a castle mound!1939, H. Lawlor, “Mote, Moat, or Motte?”, in Ulster Journal of Archaeology, 2, 208-210, p. 210
   • Deepwood is a motte-and-bailey castle in the midst of thick forest, easy to creep up on unawares. A wooden castle, defended by an earthen dike and a palisade of logs.2011, George R. R. Martin, A Dance with Dragons, page 231
2. (rhetoric) A form of argument and an informal fallacy where an arguer conflates two similar positions, one modest and easier to defend (the "motte") and one much more controversial (the "bailey"), by advancing the controversial position, but when challenged, insisting that they are only advancing the more modest position.