A term (archaic or historical) for a large triangular piece of fabric inserted in a garment to enlarge it, especially at the sides.
From grand (meaning 'large') plus gore (from Old English gara, a triangular piece of fabric). Gore is an old tailoring term; the prefix grand- emphasizes its larger size compared to standard gores used in garment construction.
This is a wonderful example of how specialized vocabulary from old trades survives in English—tailors and seamstresses developed precise terms for the different pieces of fabric used in construction. Many of these words are vanishing as traditional sewing becomes less common.
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