Difference between Unsound and Invalid

UNSOUND vs INVALID: NOUN

Any person with a disability.
One who is confined to home or bed because of illness, disability or injury
A person who is weak and infirm; one who is disabled for active service; especially, one in chronic ill health who is unable to care for himself.
Hence Something that is damaged, or the worse for wear, but not so much as to be wholly unserviceable.
An infirm or sickly person; one who is affected by disease or disabled by any infirmity.
Someone who is incapacitated by a chronic illness or injury

Not valid; of no force, weight, or cogency; weak.
In law, having no validity or binding force; wanting efficacy; null; void: as, an invalid contract or agreement.
Deficient in health; infirm; weak; sick.
To affect with disease; render an invalid: chiefly in the past participle.
To register as an invalid; enroll on the list of invalids in the military or naval service; give leave of absence from duty on account of ill health.
To cause one's self to be registered as an invalid.

Corroded, Speculative, Insecure, Dilapidated, Rotted, Bad, Rotten, Unhealthy, Insane, Unreliable, Risky, Invalid, Fallacious, Unstable, Unfit

Disable, Sophistic, Sophistical, False, Spurious, Void, Uncollectible, Specious, Fallacious, Nugatory, Expired, Unsound, Nullified, Invalidated, Null

Corroded, Speculative, Insecure, Dilapidated, Rotted, Bad, Rotten, Unhealthy, Insane, Unreliable, Risky, Invalid, Fallacious, Unstable, Unfit

Disable, Sophistic, Sophistical, False, Spurious, Void, Uncollectible, Specious, Fallacious, Nugatory, Expired, Unsound, Nullified, Invalidated, Null

We find this approach unsound for two reasons.
However, valid arguments may be sound or unsound.
But such a view would also be unsound.
The petitioner has been of an unsound mind.
Proposed Tax Legislation Is Economically Unsound and Confusing.
As the concrete deteriorates, it becomes structurally unsound.
Unsound closes with a spotlight on Bocian Records.
Applicant must not be of an unsound mind.
This diffusion of responsibility is unsound and unwise.
Persons of unsound mind The agreement with a person of unsound mind in India, is void.

Agreement is unenforceable or invalid shall not render any other provision of this Agreement unenforceable or invalid.
Use the Ignore Fields with Invalid Types property to replace data of invalid data types with default values.
Short error: Invalid Task Attribute Map Id or Invalid Task Attribute Value.
If any part of the regulations promulgated is declared invalid, all parts that are severable from the invalid parts shall remain in effect.
Once a thirdparty buys without actual knowledge of the invalid lien, that transaction will not be undone notwithstanding the invalid lien.
Directory does not automatically clean up invalid objects, but invalid objects and attributes appear in searches and can be deactivated manually.
Invalid Arrest Warrant: a criminal case WILL NOT be dismissed on the basis of an invalid arrest warrant.
Error Message: Invalid Warehouse or Warehouse Not Available You have entered an invalid warehouse.
If you enter an invalid path or name, a message appears indicating that the output MSI file name is invalid.
Will is invalid if the condition imposed is invalid or contrary to law.