1. A piece of land used for cultivation or sports that operates without proper legal authorization or permits
The farmer was fined for operating an illegal field without environmental clearance.
O agricultor foi multado por operar um campo ilegal sem aprovação ambiental.
2. In computing/data management, a data field or variable that violates established rules or constraints
The system rejected the form because it contained an illegal field entry.
O sistema rejeitou o formulário porque continha uma entrada de campo ilegal.