To slip or slide back; to return.

To fall back; to return to a former state or practice; as, to relapse into vice or error after amendment.

To fall back or return from recovery or a convalescent state; as, to relapse into a fever.

relaps’. A sliding or falling back, particularly into a former bad state, either of body or of morals; as a relapse into a disease from a convalescent state; a relapse into a vicious course of life.