1. A postponement or hold-up of unspecified or undetermined cause or duration
The flight experienced an unknown delay of several hours.
O voo experimentou um atraso desconhecido de várias horas.
2. In computing or telecommunications, a latency or wait time of indeterminate origin
The system reported an unknown delay in processing the request.
O sistema reportou um atraso desconhecido no processamento da solicitação.