Relapsing is a term used to describe the recurrence of a medical or psychological condition after a period of improvement. There are several synonyms that can be used in place of relapsing, including recurrence, backsliding, regression, setback, and deterioration. All these words imply that the patient is experiencing a decline in their condition after a period of progress. Other synonyms for relapsing include relapse, reoccurrence, resumption, repetition, and relapsation. These words can be used interchangeably, depending on the context of the situation. It is important to note that seeking immediate medical attention is critical when it comes to relapsing, to ensure proper treatment and management of the condition.