Proem and Run-up

Proem noun - A short section (as of a book) that leads to or explains the main part.

Run-up and proem are semantically related. In some cases you can use "Run-up" instead a noun "Proem".

Run-up noun - A substantial increase over a relatively short period of time.

Proem and run-up are semantically related. Sometimes you can use "Proem" instead a noun phrase "Run-up".