- ram's-head lady's slipper
- ramsons
- ramus
- rana
- rana cascadae
- rana catesbeiana
- rana clamitans
- rana goliath
- rana palustris
- rana pipiens
- rana sylvatica
- rana tarahumarae
- rana temporaria
- ranales
- ranalian complex
- ranatra
- ranch
- ranch hand
- ranch house
- rancher
- ranching
- rancid
- rancidity
- rancidness
- rancor
- rancorous
- rancour
- rand
- randall jarrell
- random
- random access memory
- random memory
- random number generator
- random sample
- random sampling
- random variable
- random walk
- random-access memory
- randomisation
- randomise
- randomised
- randomization
- randomize
- randomized
- randomly
- randomness
- randy
- ranee
- range
- range animal
- range finder
- range hood
- range in
- range of a function
- range of mountains
- range pole
- rangefinder
- rangeland
- ranger
- rangifer
- rangifer arcticus
- rangifer caribou
- rangifer tarandus
- ranging
- ranging pole
- rangoon
- rangpur
- rangpur lime
- rangy
- rani
- ranid
- ranidae
- ranier
- ranitidine
- rank
- rank and file
- rank order
- rank-difference correlation
- rank-difference correlation coefficient
- ranked
- ranker
- rankin
- rankine
- rankine scale
- ranking
- rankle
- rankness
- rank-order correlation
- rank-order correlation coefficient
- rank-smelling
- ransack
- ransacked
- ransacking
- ransom
- ransom money
- ransomed
- rant
- ranter
- ranting
- ranula
- ranunculaceae
- ranunculales
- ranunculus
- ranunculus acris
- ranunculus aquatilis
- ranunculus bulbosus
- ranunculus ficaria
- ranunculus flammula
- ranunculus glaberrimus
- ranunculus lingua
- ranunculus lyalii
- ranunculus occidentalis
- ranunculus repens
- ranunculus sceleratus
- ranvier's nodes
- raoul dufy
- raoulia
- raoulia australis
- raoulia lutescens
- rap
- rap group
- rap music
- rap session
- rap sheet
- rapacious
- rapaciously
- rapaciousness
- rapacity
- rapateaceae
- rape
- rape conviction
- rape oil
- rape suspect
- raped
- raper
- rapeseed
- rapeseed oil
- raphael
- raphanus
- raphanus raphanistrum
- raphanus sativus
- raphanus sativus longipinnatus
- raphe
- raphia
- raphicerus
- raphicerus campestris
- raphidae
- raphidiidae
- raphus
- raphus cucullatus
- rapid
- rapid city
- rapid climb
- rapid eye movement
- rapid eye movement sleep
- rapid growth
- rapid transit
- rapidity
- rapidly
- rapidness
- rapier
- rapine
- rapist
- rappahannock
- rappahannock river
- rappee
- rappel
- rappeller
- rapper
- rapport
- rapporteur
- rapprochement
- rapscallion
- rapt
- raptor
- raptores
- raptorial
- raptorial bird
- rapture
- rapturous
- rapturously
- raptus
- raptus hemorrhagicus
- rara avis
- rare
- rare bird
- rare earth
- rarebit
- rare-earth element
- raree-show
- rarefaction
- rarefied
- rarefy
- rarely
- rareness
- rare-roasted
- rarified
- rarify
- raring
- rariora