You can create a button form field and set the Reset a form action to allow users to clear any form data already filled in.

How to create a Reset Form button:

1. Choose Forms > Button Tool, or select the Button Tool on the Advanced toolbar.
2. Drag to create a button area, then open the Button Properties dialog box.
3. Click the Actions tab and select Mouse Up from the Select Trigger menu.
4. Select Reset a form from the Select Action menu, then click Add.
5. In the Reset a Form dialog box, select the individual fields from the Select Field(s) list, or click Select All to select all the fields.
6. Define the appearance and display of the button in other tabs if necessary, or click Close.

Creating a Reset Form Button