a hard-to-describe influence or quality; an important element with unknown consequences; also written X-factor
The new center on the basketball team is the X factor.
In contrast to the seriousness and heavy-handedness of late-era Idol, x factor feels positively effervescent.
Led by x factor, the Fox network won its first November sweeps with the critical 18- to 49-year-old demographic.
Her mother, Lynne Spears, left the courthouse before Bruguera issued her ruling to join her daughter on the set of The x factor.