This does not alter the field through JSON, so if you absolutely need a solution that uses JSON, this will not be the answer for you.

However, to manually get rid of the Title field, here is what you would do:

 1. Go to the list settings page for that list.
 2. Click on "Advanced Settings".
 3. At the top of the page, set "Allow management of content types" to Yes. (Click OK to save the setting.)
 4. Back in the list settings page, you should now see a "Content Types" section with the content type "Item" listed.  Click on "Item" to edit the content type.
 5. In the Content Type Information page you will see a list of all the columns included in that content type.  Click on "Title" to edit how that column behaves as part of the content type.
 6. In the "Change Content Type Column" page for the Title column, change the column settings to make it Hidden.  (Click OK to save the setting.)

You now should no longer see the Title column in the New, Edit or Display forms, and it won't be a required field.  It _is_ still technically attached to the list, though, so you will probably have to go through and edit your views to remove it from all the views.  But after that, users will no longer see any reference to it.

Alternatively, another way to handle the situation would be, if you have a single line of text field that you want as part of your list, instead of creating that as a separate field, just go in and edit the Title field, make it not required, and change the display name to be whatever you want your field to be named.  It will still be "Title" internally, but your users won't see that.