This article explains how to delete contacts on WhatsApp. Contacts will never know that you deleted them because no notifications are sent to contacts when they are deleted.
How to Delete a WhatsApp Contact – Complete Guide
The process of deleting a WhatsApp contact differs only slightly between iOS and Android. The steps below are for the iOS version:
Open WhatsApp and tap Chats.
Tap the chat composer icon in the top right corner of the Chats screen.
