(Genetics) The degree to which an expressed gene produces its effects in an organism
The degree to which a particular genotype is expressed in the phenotype The degree of expression of a genetically controlled trait
The degree to which a heritable trait is expressed in an individual "Variable expressivity" refers to the variation in phenotype and in severity produced by the same gene in different individuals
The relative constancy of the phenotype of individuals of a given genotype Mutations said to have variable expressivity show a relatively large amount of phenotypic variation among individuals having the same genotype See also Penetrance