1. (adjective) lacking principles or scruples

• rascally
• roguish
• scoundrelly

1. (adjective) lacking principles or scruples

• dishonest
• dishonorable

1. (adjective) lacking principles or scruples

• blackguard
• bounder
• cad
• dog
• heel
• hound
• devilment
• devilry
• deviltry
• mischief
• mischief-making
• mischievousness
• rascality
• roguery
• roguishness
• shenanigan
• knave
• rapscallion
• rascal
• rogue
• scalawag
• scallywag
• varlet
• scoundrel
• villain