Answer: xfactor

AnswerCrossword Clue
XFACTORUnknown
XFACTORUnpredictable determinant
XFACTORHard-to-define element
XFACTORNebulous element
XFACTORUnknown influence
XFACTORIts effect is hard to predict
XFACTORStrongly influential quality
XFACTORHard-to-define influence
XFACTORUnpredictable element
XFACTORUnknown element
XFACTORJe ne sais quoi
XFACTORElement of surprise?