unknownfactor
nounUK /ʌnˈnəʊn ˈfæktə/
US /ʌnˈnoʊn ˈfæktər/
An unknown factor is something you do not know that can change what happens.
The weather is an unknown factor in our picnic plans.
OTHER MEANINGS
2. In math, a number in a multiplication problem that you do not know yet.
In 4 times x equals 20, x is the unknown factor.
3. Something hidden that makes a result hard to predict.
The broken part was the unknown factor in why the machine stopped.
4. A person or thing whose effect on a situation is not yet clear.
The new player is an unknown factor for the team this season.