Thank you for your further comment.
I would like to include neat tooltips in my pdf files so that information, such as word definitions/further examples etc. can appear the mouse is hovered on a particular word. Therefore, I would like the files to feature no text fields or buttons (as I do not want to actually use form fields to fill), but rather, the simple floating tooltip text in relation to a specific word in a specific position. I do understand that this is not what tooltips are meant for.
I have made some progress, as one can perhaps tell from the attached file. Unfortunately, the tooltip only works when the Form Field in the Text Field General Properties is marked as Visible. It stops working if it is marked as Hidden. But the visibility of the text field (in pale shade of blue) is distracting and not aesthetically pleasing.
Use a button field to trigger the tooltip. Remove the border and fill from the button appearance properties, so it is essentially invisible.