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