retroaction (?.)
- action and reaction
- answer
- automatic reaction
- autonomic reaction
- backset
- backsliding
- backward motion
- backward step
- bounceback
- echo
- lapse
- predictable response
- reaction
- recession
- recidivation
- recidivism
- reentry
- reflection
- reflex
- reflex action
- refluence
- reflux
- regress
- regression
- relapse
- reply
- respondence
- response
- retrocession
- retroflexion
- retrogradation
- retrogression
- retrusion
- return
- reverberation
- revulsion
- rise
- rollback
- setback
- sternway
- throwback
- unthinking response
