correlation_coefficient
1. [ noun ] (mathematics,statistics) a statistic representing how closely two variables co-vary; it can vary from -1 (perfect negative correlation) through 0 (no correlation) to +1 (perfect positive correlation)
Synonyms: correlation coefficient_of_correlation
Examples:

"what is the correlation between those two variables?"

Related terms: parametric_statistic multiple_correlation_coefficient product-moment_correlation_coefficient biserial_correlation_coefficient split-half_correlation tetrachoric_correlation_coefficient statistics
Similar spelling:   correlational_statistics