adverb
thereon
thair-AHN/ˌðerˈɑːn/
On that thing or surface.
The child places the bowl on the table and leaves it thereon.

Etymology
The pieces place something on top of what “there” identifies. Rather than naming the supporting surface again, “thereon” points back to it, preserving the concrete sense “on that thing.”
In context
buttonholes appear three inches apart from each other thereon.
and of the name of the author if it appears thereon.
More examples
- Please read the notice and follow the instructions printed thereon.
- The marble slab bears a name carved thereon.
- The buyer accepts the property with all improvements thereon.
Forms
thereon
Similar words
- thereupon
- Also means on that, but can mean immediately afterward.