Multiple Line Text Box 
To add a Multiple-Line Text Box field to the User Profile form, click on the following to your left: User Profile Fields> Add New User Profile Field then select Multiple-Line Text Box from the dropdown menu.

The Multiple-Line Text Box form allows you to add a custom multiple line text box field to the User Profile form.
You must click Save for changes to take effect.
Add New User Profile FieldDisplay Page
Multiple-Line Text box fields can not be listed on the Members List.
User Contributed Notes: Multiple Line Text Box