1. An area or region whose boundaries, characteristics, or limits are unclear, vague, or not precisely established
The disputed territory remains an ill-defined zone between the two countries.
O território disputado permanece uma zona mal definida entre os dois países.
2. In technical or scientific contexts, a space or field where parameters are ambiguous or lack clear demarcation
The transition from the urban to rural areas creates an ill-defined zone.
A transição da área urbana para a rural cria uma zona mal definida.