Nan

Part of speech: noun

Definitions

1. An informal British word for a grandmother, often used by children when speaking about or to their gran ; a placeholder value in computing that marks an undefined or unrepresentable numeric result
2. A familiar, affectionate term for one's grandmother ; a special floating-point value signalling that a calculation has produced no valid numerical answer
3. Informal name for a grandmother, especially in Britain ; a marker value in programming meaning the result of an operation is not a number

Etymology: The word "nan" as a name for a grandmother began as a pet form of two very common women's names, Anne and Agnes. Before it reached the nursery, the same sound had already been used for a nursemaid, which reveals how close family and childcare roles were in the naming habits of earlier centuries. Those personal names were so widespread that "Nan" became a generic label for any woman caring for children. The more familiar sense came from a related word, "nana," which was itself a shortening of "nanny." That earlier form was shaped partly by "mama," so the baby-talk vocabulary of the nursery pulled the pieces into a shape that children could easily repeat. Clipping "nana" down to "nan" left a single syllable that suited a grandmother's affectionate title.

Synonyms: grandma, granny, grandmother, gran, nana