n. Descent of related families; distinction between the members of a family according to their ages. [ 1913 Webster ]

Marks of cadency (Her.), bearings indicating the position of the bearer as older or younger son, or as a descendant of an older or younger son. See Difference (Her.). [ 1913 Webster ]

{ } n. [ LL. decadentia; L. de- + cadere to fall: cf. F. décadence. See Decay. ] A falling away; decay; deterioration; declension. “The old castle, where the family lived in their decadence.” Sir W. Scott. [ 1913 Webster ]

n. A falling back or descending a second time; a relapse. W. Montagu. [ 1913 Webster ]