Yes, notifications can be silenced for one person on iPhone. To do this, follow these steps:
1. Open the Messages app and select the conversation with the person you want to silence.
2. Tap on the "i" icon in the top right corner of the screen.
3. Scroll down and toggle on the "Hide Alerts" option.
4. This will silence notifications for that specific conversation, so you won't receive any notifications when they message you.
5. To undo this, simply repeat the steps and toggle off the "Hide Alerts" option.
By following these steps, you can silence notifications for one person on your iPhone without affecting notifications from other conversations or contacts.