controlled variable
nounA controlled variable is something a scientist keeps the same in every test so it does not change the results.
In our plant experiment, the amount of water was a controlled variable because we gave every plant the same amount.
OTHER MEANINGS
2. In math, a controlled variable is a value that is kept fixed on purpose while other values change.
The teacher treated the starting number as a controlled variable so the pattern stayed clear.
3. In engineering, a controlled variable is the thing a system adjusts to keep at a set level.
In the oven, the temperature is the controlled variable that the thermostat keeps steady.
4. In everyday planning, a controlled variable is a factor you decide to keep the same to make a comparison fair.
When comparing two routes to school, the time of day was a controlled variable.