You can delete specific items instead of your whole history by tapping or clicking the ⋮ button next to an item in your “Item view” list and selecting “Delete. "
Previous searches will only appear if you are signed into Google.
Note: The black results are autocomplete results based on common or popular searches. They cannot be deleted and have no bearing on your local search history.
On mobile devices, you’ll need to tap “OK” in the pop-up that appears to confirm.