Yes, you can hide or unpublish an Auction item at any point before, during, or after the Auction!
1. From your dashboard, head to Auctions and click Manage on your selected Auction.
2. Click Items in the left sidebar and find the item you wish to hide or unpublish. Click on the 'eye' icon on the item's top right-hand corner.
3. This will hide or unpublish the item from your auction.
To undo this, simply click on the 'eye' icon again.