Definition of retrocalculation in US English:

retrocalculation

noun

  • The action or process of calculating retrospectively; an instance of this.

Origin

Mid 17th century; earliest use found in Henry Power (c1626–1668), natural philosopher and physician. From retro- + calculation.

Pronunciation

retrocalculation

/ˌrɛtrəʊkalkjʊˈleɪʃn/