definition of
relapse

[1] #1 relapse n. [backsliding, lapse, lapsing, relapsing, reversion, reverting] a failure to maintain a higher state. wn

[2] #2 relapse v. [get worse] deteriorate in health; "he relapsed". wn

[3] #3 relapse v. [lapse, recidivate, regress, retrogress, fall back] go back to bad behavior; "Those who recidivate are often minor criminals". wn