The hearing was agendum to next Tuesday after the court requested more documents.

在法庭获取更多文件，证会将于下周二举行。

I've  never heard anyone call an item on the agenda an " agendum" .

我从未过有人将议程上的项称为“议程”。

The nearest equivalent is agenda, an old plural of agendum, " something to be acted on" .

最接近的等价词是 agenda，agendum 的旧复数形式，“要采取的行”。

Normally, words would tend toward the regular pattern of  adding " -s" or " -es" to make them plural — like how " agendum" became " agendas" and " hippopotami"   became " hippopotamuses" — but a few words tended toward the irregular pattern of zero plurals  instead.

正常情况下，单词会倾向于添加“-s”或“-es”来使其成为复数的常规模式 - 例如“agendum”变成“agendas”，“hippopotami”变成“hippopotamuses” - 但少数单词却倾向于不规则的零复数模式。