1. mischievous or playfully naughty people, especially children
Usage: informal; often used affectionately
2. dishonest or unscrupulous people
Usage: can be used seriously or humorously

Examples

• Those little rascals drew all over the walls with crayons.
• The children were such rascals during the field trip.
• Don't trust those rascals with your money.
• The old rascals were caught cheating at cards again.
• She called her grandchildren lovable little rascals.
• The movie featured a group of charming rascals planning a heist.