I read an article about Test Driven Datamigration (German, PDF) and they mentioned a Sanity Suite. It is not well explained and there's no definition.
Is there a definition or is it a spongy word?
This is a small set of unit or integration tests, just to check sanity -- that the system basically works.
It can be useful to extract such a suite from your larger suite of automated tests for rapid testing when you don't have time for the full suite.
In practice, the sanity suite is often all that is developed, though it is better than nothing.