Meaning of undeclared

1. The student was caught with an undeclared weapon in his backpack.
2. The company made an undeclared profit from their latest deal.
3. The politician's undeclared connections to the oil industry were revealed in a leaked document.
4. The traveler was detained at the airport for carrying undeclared goods in his luggage.
5. The athlete was disqualified from the competition for taking undeclared performance-enhancing drugs.
6. The government issued a warning about the dangers of buying undeclared prescription medications online.
7. The company faced fines for hiring undeclared workers without proper documentation.
8. The country's undeclared nuclear program raised concerns among neighboring nations.
9. The artist's undeclared income from selling counterfeit merchandise landed him in legal trouble.
10. The student was expelled from school for submitting an undeclared plagiarized essay.