If you search your address book after a while, you'll find that some contacts in it can be easily removed.
If you don't know how to delete a single contact, we've written a guide for you:
Please follow our step-by-step instructions:
How to remove a contact on iPhone under iOS.
1. Open the Contacts app or Phone app and tap "Contacts" below.
2. Select the contact you want to delete.
3. Tap the "Edit" button in the upper right corner.
4. Scroll all the way down and tap Delete Contact.
5. Tap "Delete" again to confirm the operation.
You have just successfully removed a contact from your iPhone.
Do this for individual contacts that you no longer want to store in your address book.