various things; all sorts of things; many things
Refers to a collection of diverse items, matters, or people. Often used when listing or summarizing multiple things without specifying each one. The 'large number of people' gloss is a less common extension; the core meaning is 'various things'.
For various reasons, I wasn't able to take part this time.
I'm busy with various procedures for the move.
会議では、もろもろの問題について話し合った。
At the meeting, we discussed various issues.
Let's discuss the costs and everything else together later.
諸事 is a stiff, written term for 'various matters' used in formal notices, while 諸々 is slightly more flexible and can appear in ordinary formal speech too.
Standard kanji spelling; the repetition mark 々 is the most common written form.
Kana spelling; used when the kanji might be unclear or for emphasis.
Full kanji spelling without the repetition mark; less common but still encountered.
Single-character spelling; rare and mostly found in older or formal contexts.
The reading もろもろ is a reduplication of もろ (諸), which itself is of uncertain origin. The kanji 諸 means 'various' or 'many'.