1. An explanation or account that lacks a solid factual or logical basis; a claim or reasoning that is not supported by evidence or valid grounds
The theory he presented was merely an unfounded explanation for the sudden market crash.
A teoria que ele apresentou era apenas uma explicação infundada para o súbito colapso do mercado.
2. A statement offered as an explanation that is based on assumption or conjecture rather than established facts
Her unfounded explanation for his absence was rejected by the committee.
Sua explicação infundada para a ausência dele foi rejeitada pela comissão.