thereon

Thereon is an adverb meaning on that thing, on that matter, or on the document or surface previously mentioned. In modern English it is relatively formal or archaic and is most often found in legal drafting, historical writing, and certain literary texts. It refers to something already named or shown, rather than introducing new information.

Etymology: It derives from Old English thereon, combining there + on. It shares a family with other adverbs such as therein, thereupon, therein, thereat, which attach to a noun or document to point back to it.

Usage notes: Thereon typically follows a noun when used in a postmodifier position: “the map thereon shows the route.” It can also occur before a clause, as in “Thereon lies the problem,” though this usage is uncommon outside formal prose. In legal writing, thereon governs phrases like “terms thereon” or “conditions thereon,” meaning “on that document or matter.” For everyday writing, use on that, on it, or on which instead to avoid archaism.

Examples: The form, thereon the applicant’s name is written. The contract is attached; thereon lie the obligations of the parties. A map is included, thereon the routes are marked.

See also: therein, thereupon, thereat, thereof, therefrom.