due to an unknown cause, for a reason that is not clear

الإنجليزية - الإنجليزية

تعريف due to an unknown cause, for a reason that is not clear في الإنجليزية الإنجليزية القاموس.

for some unknown reason

الواصلة

due to an un·known cause, for a rea·son that I·s not clear