unscrupulous

Unscrupulous, unprincipled refer to lack of moral standards or conscience to guide one's conduct. The unscrupulous person is without scruples of conscience, and disregards, or has contempt for, laws of right or justice with which he or she is perfectly well acquainted, and which should restrain his or her actions: unscrupulous in methods of making money, in taking advantage of the unfortunate. The unprincipled person is without moral principles or ethical standards in his or her conduct or actions: an unprincipled rogue; unprincipled conduct.