What's the precise meaning of "landing south (north, east, west)" in STARs?
"Landing south" means the planes are facing south as they land. Depending on conditions, they could come from the opposite end of the runway, and would be "landing north." This is also referred to as "south flow/operations."

If you look at a chart for the IVANE FIVE shown below, you can see why this is important. The runways at KCLT are primarly oriented north/south. The aircraft will enter the approach at MAJIC from the northeast. If landing south, the arriving airplane will fly IVANE BABZE HEELZ and needs to be at 6000 feet when they reach HEELZ north of the airport. Approach control will then turn them south to land. If landing north, they will fly from IVANE to GIZMO and follow the approach down to the south, and don't have to be at 6000 until they get down to ESENE. After reaching JATAB approach turns them north to land.

Telling the pilots which direction they will be landing lets them know which route to follow on the approach and helps them plan their descent. If approach hasn't provided a runway yet, they can also know which runways they can plan for.



Source. This is the best I could find for the IVANE arrival. The MAJIC ONE isn't RNAV, the CHSLY THREE would seem to be the applicable RNAV procedure from the northeast.