Merriam-Webster's Collegiate Dictionary:
retread
retreat
retreatant
retreater
retrench
retrenchment
retrial
retribalization
retribution
retributive
retributively
retributory
retrievability
retrievable
retrieval
retrieve
retriever
retro
retro-
retro-rocket
retroaction
retroactive
retroactively
retroactivity
retrocede
retrocession
retrodict
retrodiction
retrodictive
retrofire
retrofit
retroflection
retroflex
retroflexion
retrogradation
retrograde
retrogradely
retrogress
retrogression
retrogressive
retrogressively
retropack
retroperitoneal
retroperitoneally
retroreflection
retroreflective
retroreflector
retrorse
retrospect
retrospection
retrospective
retrospectively
retrouss?
retroversion
retroviral
retrovirologist
retrovirology
retrovirus
retsina
return
returnable
returnee
returner
retuse
retz
reuben
reuchlin
reunion
reunionist
reunionistic
reunite
reuptake
reusability
reusable
reuse
reuter
reuther
reutlingen
rev
revaluate
revaluation
revalue
revamp
revanche
revanchism
revanchist
revascularization
revd
reveal
revealable
revealer
revealing
revealingly
revealment
revegetate
revegetation
reveille
