Relapse (r-lps), v. i. [imp. & p. p. Relapsed (-lpst); p. pr. & vb. n. Relapsing.]
Etymology: [L.relapsus, p. p. of relabi to slip back, to relapse; pref. re- re- + labi to fall, slip, slide. See Lapse.]
1. To slip or slide back, in a literal sense; to turn back. [Obs.] Dryden.
2. To slide or turn back into a former state or practice; to fall back from some condition attained; -- generally in a bad sense, as from a state of convalescence or amended condition; as, to relaps into a stupor, into vice, or into barbarism; -- sometimes in a good sense; as, to relapse into slumber after being disturbed. That task performed, [preachers] relapse into themselves. Cowper.
3. (Theol.)
To fall from Christian faith into paganism, heresy, or unbelief; to backslide. They enter into the justified state, and so continue all along, unless they relapse. Waterland.
1 other Webster entry under this spelling
Relapse, n.
1. A sliding or falling back, especially into a former bad state, either of body or morals; backsliding; the state of having fallen back. Alas! from what high hope to what relapse Unlooked for are we fallen! Milton.
2. One who has relapsed, or fallen back, into error; a backlider; specifically, one who, after recanting error, returns to it again. [Obs.]