The Collaborative International Dictionary of English v.0.48:
hierarchic \hi`er*arch"ic\, hierarchical \hi`er*arch"ic*al\, a. [Cf. F. hi['e]rarchique.] Of or pertaining to a hierarchy; ordered in a hierarchy. -- Hi`er*arch`ic*al*ly, adv. Syn: hierarchical, hierarchal. [1913 Webster] 2. Pertaining to a transitive relation between objects by which they may be ordered into a hierarchy; as, a hierarchical relation. [PJC]