[ad.he.sion] n [F or L; F adhesion, fr. L adhaesion-, adhaesio, fr. adhaerere] (1624) 1: steady or firm attachment: adherence
2: the action or state of adhering
3: the abnormal union of separate tissue surfaces by new fibrous tissue resulting from an inflammatory process; also: the newly formed uniting tissue
4: agreement to join "~ of all nations to a copyright convention"
5: the molecular attraction exerted between the surfaces of bodies in contact -- ad.he.sion.al adj