unscrupulous

/ˈʌnˌskrupjələs/

/ənˈskrupjuləs/

Use the adjective unscrupulous to describe someone who behaves in a dishonest or unethical way.

Unscrupulous behavior is the unfortunate resort of many ambitious people — it’s the immoral stuff they do to make success more attainable. When you sell someone bad loans, when you hack into your competition's accounts, when you read your roommate's mail for signs of an opportunity with his girlfriend, you're being unscrupulous.

Definitions of unscrupulous

1. adjective

   without scruples or principles
   “unscrupulous politicos who would be happy to sell...their country in order to gain power”

   synonyms:

   amoral, unprincipled

   lacking principles or moral scruples

   antonyms:

   scrupulous

   having scruples; arising from a sense of right and wrong; principled

   principled

   based on or manifesting objectively defined standards of rightness or morality

   religious

   extremely scrupulous and conscientious