Definition for Heritability
From Biology Forums Dictionary
1. The proportion of total phenotypic variation in a trait attributable to genetic variation; determines the potential for evolutionary change in a trait.
2. Heritability is the amount of variability within a group, raised in the same environment, that is due to genetics. It does not apply to between-group differences.
3. It is a statistical measure that quantifies the influence of genes on phenotypic variance with respect to a given trait.