An act of alluding, returning, or reverting (to a subject previously mentioned, etc.); also, an act of evoking, or longing or pining for (a past era or event).
An act of hounds retracing a course in order to pick up the lost scent of prey.
A retrogression.
To return to an earlier, simpler or worse condition; to regress.
To go backwards; to retreat.
To return to bad behaviour; to relapse.