1.
You use ~ to indicate that there are two aspects or features that are having an influence on a particular situation.
The new tax and the drop in house values make homeowners feel ~ penalised.
ADV: ADV group, ADV with v
2.
You use ~ to emphasize that something exists or happens to a greater degree than usual.
In pregnancy a high fibre diet is ~ important...
ADV: ADV adj/adv emphasis