1
general::
Small amounts of money for incidental expenses, as in Grandma usually gives the children some pin money whenever she visits. This expression originally signified money given by a husband to his wife for small personal expenditures such as pins, which were very costly items in centuries past. A will recorded at York in 1542 listed a bequest: "I give my said daughter Margarett my lease of the parsonage . . . to buy her pins." [Early 1500s]
American Heritage Idioms