Probably "previous" - can you give us an example sentence?

I just want to give an overview of lectures from former (or previous...) terms and of planning of upcoming (or forthcoming...) terms.

In German it would be "vergangene Semester" and "zukünftige Semester".

Ich schätze, dass ist wie im Deutschen mit "vorangegangen(e)" und "früher(e)".

sorry: "das"

"Previous terms", then. Combined with "lectures" you might also use "past": an overview of past lectures.

A former postman is a man who was a postman in the past (now he's got a different job, or has stopped working).
Our previous postman is the postman we had before our current postman.