SharePoint workflow can be categorized to site workflow, list workflow and reusable workflow. List Workflow is workflow which is Associated with one particular List. It waits for events happened on that specific list and start actions pre-configured.
A simple introduction blog:http://devendra-sharepoint.blogspot.com/2012/02/list-workflow-vs-reusable-wokflow-...
PowerShell script to hide a SpFeature
Credits to Brandon Atkinson:
This best way to do this is in the code for the feature. The feature
has a Hidden flag you can set. Check this post for details:
So, if you have the code, set that and re-deploy.
If you don't have the code, check this blog post: