1. Pertaining to genes in a homozygote that are copies of the same ancestral gene as a result of a mating between related individuals.
2. Indicating genes in a homozygote that are copies of the identical ancestral gene as a result of a consanguineous (common ancestor) mating.

A homozygote is a nucleus, cell, or organism with identical alleles ( forms of the same gene) of one or more specific genes.