pecuniary legacy (def.)
A gift of a fixed sum of money in a Will, for example "£5,000 to my niece".
A pecuniary legacy is one of three ways you can leave something in your Will. The others are a specific gift, which is a named item such as a piece of jewellery, and a share of your residuary estate, which is a percentage of whatever remains once everything else has been dealt with.
If your estate is not large enough to pay all the pecuniary legacies in full, they are usually reduced proportionately.