Familial means to do with a family, or running in one. Familial ties, a familial condition, familial obligation.
In medicine it is precise and means inherited, so a familial condition appears in relatives more often than chance would explain. Elsewhere it means simply of the family, and it is a shade more formal than family as an adjective.
1adjectivefamilialTo do with a family, or running in one.
“The two cousins share a strong familial resemblance, with the same red hair and freckles.”
familial is a quality.