1. A fundamental or core matter that is vital to a discussion, decision, or situation; the crux of the matter
The essential issue in this debate is whether the government should regulate industry more strictly.
A questão essencial neste debate é se o governo deve regular a indústria mais rigorosamente.
2. In legal contexts, a matter that is absolutely necessary or critical to a case or contract
The court ruled that the breach of contract dealt with an essential issue that voided the agreement.
O tribunal decidiu que a violação do contrato abordava uma questão essencial que anulava o acordo.