Definition of post scriptum in US English:

post scriptum

noun

  • Postscript.

Origin

Early 16th century. Apparently from classical Latin post after + scrīptum script, perhaps after Middle French postscript. Compare classical Latin postscrībere, of which the expected neuter past participle form would be *postscrīptum, although the past participle of this verb is not in fact attested. Compare French post-scriptum, Italian post scriptum; also German Postskriptum, Swedish postskriptum.

Pronunciation

post scriptum

/ˌpəʊs(t) ˈskrɪptəm/