The phrase "not scruple to do something" is often used as a way to describe a person who is willing to do something without hesitation or moral qualms. Synonyms for this phrase include, but are not limited to: be unprincipled, be unscrupulous, be shameless, be audacious, be bold, be daring, be fearless, have no compunctions, have no qualms, have no reservations, have no scruples, have no shame, and have no sense of morality. Using these alternatives can add variety and depth to your writing by allowing you to convey the same concept in different ways.