What is the meaning of relapsing?

noun

• A failure to maintain a higher state.
  • synonyms: backsliding, lapse, lapsing, relapse, reversion, reverting

verb

• Deteriorate in health.
  • usage: "he relapsed"
  • synonyms: get worse, relapse
• Go back to bad behavior.
  • usage: "Those who recidivate are often minor criminals"
  • synonyms: relapse, lapse, recidivate, regress, retrogress, fall back