Merriam-Webster's Collegiate Dictionary:
request
requester
requestor
requiem
requiem shark
requiescat
requiescat in pace
require
requirement
requisite
requisiteness
requisition
requital
requite
requiter
reradiate
reradiation
reredos
rereward
rerun
res
res adjudicata
res gestae
res judicata
res publica
resalable
resale
rescale
reschedule
rescind
rescinder
rescindment
rescission
rescissory
rescript
rescuable
rescue
rescue mission
rescuer
research
researchable
researcher
researchist
reseau
resect
resectability
resectable
resection
reseda
reseed
resemblance
resemblant
resemble
resend
resent
resentful
resentfully
resentfulness
resentment
reserpine
reservable
reservation
reservationist
reserve
reserve bank
reserve clause
reserve price
reserved
reserved power
reservedly
reservedness
reservist
reservoir
reset
resettable
resh
reshape
reshaper
reshuffle
resid
reside
residence
residence time
residency
resident
resident commissioner
residential
residential college
residentially
resider
residual
residual oil
residual power
residually
residuary
residue
residue class
