Dissuade Interaction is a wiki pattern designed to reduce conflict caused by problem users on your wiki.
Whilst problem users can be blocked, they may find ways of circumventing the block and returning to the wiki. Maintaining a relationship with them, even a negative one, by responding to their edits or getting into a fight may encourage them to keep on returning. By dissuading interaction with them, not responding to them, not drawing attention to their edits, you make it less fun for them to troll you or for them to vandalize your wiki.
Dissuading interaction can save you time by preventing the need to respond to pointless posts by someone the community does not welcome on their wiki. This technique can also be useful for users you find upsetting your wiki but who are not doing anything bad enough to be blocked.
However, be aware that dissuading interaction might be seen as passive aggressive behavior and won't help in matters where miscommunication is the problem.
See also Dissuade Reputation and Vandalism is not a game.