Though-provoking is a related term of challenging.
As a verb challenging is
As an adjective challenging is
difficult, hard to do.
As a noun challenging is
the act of making a challenge.
Not English Though-provoking has no English definition. It may be misspelled.
The act of making a challenge.
* Estcourt Rowland Metzner, The conflict of tax laws (page 151)
- There are always sincere challengings of the findings, always the objections (sincere in another sense) of those whose interests seem threatened.