Definition of post festum in US English:

post festum

adverb

  • = post factum. In quot. 1966 ‘after the festival’.

Origin

Late 19th century. From German post festum, transferred use of post-classical Latin post festum after the feast from classical Latin post after + festum festival, feast-day.

Pronunciation

post festum

/ˌpəʊs(t) ˈfɛstəm/