old money

Short definition from Wiktionary

Noun

1. 1
   Families that have been wealthy for generations or members of such families.
2. 2
   The monetary system used in the United Kingdom and Ireland before decimalisation in 1971 and consisting of pounds, shillings, pence and farthings.
3. 3
   The imperial system of measurement or Fahrenheit, as opposed to the metric system or Celsius.