Merriam-Webster's Collegiate Dictionary:
representative
representatively
representativeness
representativity
representer
repress
repressed
repressibility
repressible
repression
repressionist
repressive
repressively
repressiveness
repressor
reprieval
reprieve
reprimand
reprint
reprinter
reprisal
reprise
repristinate
repristination
repro
reproach
reproachable
reproacher
reproachful
reproachfully
reproachfulness
reproachingly
reprobance
reprobate
reprobation
reprobative
reprobatory
reprocess
reproduce
reproducer
reproducibility
reproducible
reproducibly
reproduction
reproduction proof
reproductive
reproductive isolation
reproductively
reprogram
reprogrammable
reprographer
reprographic
reprographics
reprography
reproof
reprove
reprover
reprovingly
rept
reptile
reptilian
republic
republic of georgia
republic of the congo
republican
republicanism
republicanize
republication
republish
republisher
repudiate
repudiation
repudiationist
repudiator
repugn
repugnance
repugnancy
repugnant
repugnantly
repulse
repulsion
repulsive
repulsively
repulsiveness
repurchase agreement
repurpose
reputability
reputable
reputably
reputation
reputational
repute
reputed
reputedly
req
reqd
request
