The phrase "a purpose for which" is correct and usable in written English.
It can be used to specify the reason or intention behind an action or object.
Example: "The committee was formed for a purpose for which we all agreed upon: to improve community engagement."
Alternatives: "a reason for which" or "an aim for which".
Stop using Social Security numbers as de facto identity numbers, a purpose for which they were never intended.
Technically, doctors can prescribe drugs for a purpose for which they are not licenced, but charities and clinicians said that most seek the assurance of a licence before prescribing.
The German government has called on Elon Musk's company to stop using the Autopilot branding, while the maker of the original version decided to stop selling it to Tesla, accusing the electric car company of "pushing the envelope" on safety by using the system for a purpose for which it was never designed.
But it's impossible to see a world where we keep libraries open simply to pretend they still serve a purpose for which they no longer serve.
However, thruster cavitation was raised as a key problem when using thrusters for a purpose for which they were not intended.
Another recommendation the government has rejected is the justification of "economic well-being", linked to national security, as a purpose for which some of the powers set out in the bill can be used.
If there is a God, he clearly had a purpose for Fred Phelps, which was to show just how repulsive his ideas about man and God really are, and to warn us off them.
This is a central purpose for which horses were used in Anglo-Saxon England, particularly in warfare, since conflict between the various Anglo-Saxon kingdoms was carried out over long distances.
In conclusion, WLF-DEE-C K promotes itself as a new metric for predicting the perceived magnitude of contrast between an original and a reproduction, fulfilling the purpose for which it was developed.
What counted more was the ebbing of the idea that America was at war for a purpose of which it could feel proud.
The House of Lords held that a minister's power under an Act is not unfettered, and that the Minister in question had effectively frustrated the objects of the statute as his non-exercise of the power had been based on a misunderstanding of the purpose for which the power was given to him.
