Unscrupulous means lacking or unrestrained by scruples, unethical.
Unscrupulous is an adjective.
Synonyms: corrupt, unprincipled, disreputable, immoral, unethical, dishonest.
Antonyms: honorable, ethical, moral, principled.
I refuse to do combine studies with an unscrupulous man like Mr.Sai.
Mr.Ravi is the most honorable man I know; he would never do anything that was unscrupulous.
The unscrupulous political leader made promises he had no intention of keeping.
An unscrupulous broker sold Durga the worthless books.