The scientist was intrigued by the concept of the known unknown in the field of quantum physics.
known unknown
Frequency:
30
%
The detective faced a known unknown when trying to solve the mysterious case.
Idiomatic Expressions for known unknown
Phrase: known unknown
Meaning: something that is recognized as not being fully understood or clear
Usage: This phrase is often used in discussions about complex topics or situations where there are aspects that are acknowledged to be uncertain or not yet discovered.