- An individual directly related to an ancestor, such as a child, grandchild, or great-grandchild, continuing onward indefinitely. This differs from a 'collateral' descendant who is related through siblings, aunts, or uncles
- Her claim to the family heirloom is legitimate as she's a lineal descendant of the original owner.
- Although a nephew to the deceased, he was not considered a lineal descendant and therefore did not stand to inherit.
- Being a lineal descendant, the family house passed onto her directly from her grandmother.