unscrupulous

Synonyms: arrant base casuistic conscienceless corrupt crafty crooked deceitful degraded degrading disgraceful dishonest dishonorable exploitative illegal improper low-down mercenary perfidious petty questionable recreant ruthless scandalous scheming selfish self-seeking shady shameless shifty sinister slippery sly two-faced unconscientious unconscionable underhand underhanded unethical unfair unprincipled unworthy venal wicked wrongful

Antonyms: ethical good moral principled scrupulous