Depending on exactly what you're after, you may wish to just stop future updates to that attribute, or you want to hide it all together. To do either of these:
- Click on 'Manage Attributes' in your sidebar - Edit the Attribute you wish to hide - Scroll down to 'Attribute Admin' - If you want to just block future updates, set Active to 'No' - If you want to block updates and hide that attribute, set Active and Display to 'No'