Merriam-Webster's Collegiate Dictionary:
resuscitate
resuscitation
resuscitative
resuscitator
resveratrol
ret
retable
retail
retailer
retailing
retain
retained object
retainer
retake
retaliate
retaliation
retaliative
retaliatory
retard
retardant
retardate
retardation
retarded
retarder
retch
retd
rete
retell
retelling
retention
retentive
retentively
retentiveness
retentivity
retenue
rethink
rethinker
rethondes
reticence
reticency
reticent
reticently
reticle
reticular
reticular formation
reticulate
reticulated giraffe
reticulately
reticulation
reticule
reticulocyte
reticuloendothelial
reticuloendothelial system
reticulum
retin-
retina
retinaculum
retinal
retinene
retinitis
retinitis pigmentosa
retino-
retinoblastoma
retinoic acid
retinoid
retinol
retinopathy
retinoscopy
retinotectal
retinue
retinula
retinular
retire
retired
retiredly
retiredness
retiree
retirement
retiring
retiringly
retiringness
retool
retort
retort pouch
retouch
retoucher
retract
retractable
retractile
retractility
retraction
retractor
retrain
retrainable
retranslate
retranslation
retread
