great-grandmother

The compound 'great-grandmother' is built on the foundational kinship term 'mother', a word of ancient Proto-Indo-European origin. The prefix 'grand-', entering English via French from Latin 'grandis', was adopted in the 13th century to designate a relationship one generation removed, as in 'grandmother'. To extend this lineage further back, the intensifying prefix 'great-' (from Old English 'grēat') was systematically added, a pattern established in Middle English. Thus, the term follows a logical, additive structure where each prefix ('grand-', then 'great-') signifies an additional step of generational ascent, precisely denoting the mother of a grandparent.

Structure: great (intensifier) + grand (higher generation) + mother (parent) great (Old English 'grēat', meaning large or important, used here as an intensifying prefix); grand (Middle English, from Anglo-French 'graund', from Latin 'grandis', meaning great or large, used to denote a family relationship one generation removed); mother (Old English 'mōdor', from Proto-Germanic 'mōdēr', from Proto-Indo-European 'méh₂tēr', meaning mother).