All grocery names in the auto complete lists are crowdsourced from Grosh users per language. We do not have resources to check all items submitted, but fortunately it's easy for you to help. If you spot a spelling mistake, e.g. when adding an item - please add the item to your list and correct the spelling. You'll be asked if you were correcting a spelling mistake and tap Yes. Then you should not see the spelling mistake anymore. The system learns from your actions, and if others do the same, the misspelled item is removed from the system.
If you're used to changing an item to another item by changing the name in the grocery details screen, just tap No when asked if you were fixing a spelling mistake.
If you've tapped Yes by mistake, just add any item to the list and change the item name to the name you've blacklisted. Then tap No when asked if you were fixing a spelling mistake - this will lift the ban of the grocery name from your lists. Or you can navigate to Settings and tap Adjust next to "blacklisted groceries".