It means descendant, reindeer, shank, successor, heir. It can also mean native, native, natural, born. Another meaning may be work, creation, production, product.
Direct descendant, is named with respect to its parents. It comes to us from Latin filius, i with equal meaning.
Son: element emanated from another, which inherits a genotype, a karyotype or a philosophy-- of man: future human generation, appearing as an exogenous or endogenous effect between parents. New wave or generation at the end of a decade. The man later or more contemporary.
only begotten - only child