third variable
nounUK /ˌθɜːd ˈveəriəbl/
US /ˌθɝːd ˈveriəbl/
A third variable is an extra thing that can change how two other things are connected.
The researchers found that age was a third variable affecting the link between exercise and mood.
OTHER MEANINGS
2. In math, a third variable is a third unknown number in an equation that has three unknowns.
The equation has three unknowns, so we solve for the third variable last.
3. In programming, a third variable is a temporary extra variable used to swap or store values.
Use a third variable to swap the values of a and b.
4. In an experiment, a third variable is any additional factor the scientist measures or controls.
They recorded temperature as a third variable to check for hidden effects.