or as security for a debt. 3 Indirect; on a parallel or diverging line. collective mark collateral ascendant. A relative, such as an aunt, uncle, or cousin, who has a common ancestor with a person but is not that person's ancestor. Also called collateral. See also ancestor and descendant. collateral attack.An attack in a judicial proceeding against another judicial proceeding or a judgment entered in another court. For example, a party in Florida may attack a judgment entered against him by a...