Countable Nouns That Start with O and End with R
Explore 212 verified English countable nouns starting with O and ending with R, including Order, Offer, Owner, Officer, Operator, Outer and Oliver. Sort these count nouns with singular and plural forms by word length for ESL grammar practice, determiner usage, and plural spelling below, or review singular and plural count rules in our noun grammar guide.
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Starts with OA
2 words oar
oater
Starts with OB16 words
observer
objector
obligor
obturator
obstructor
obiter
obsessor
obtainer
obliterator
obeyer
obliger
obviator
obligator
observator
obtruder
objurgator
Starts with OC15 words
ocular
occupier
ocher
oceanographer
oculomotor
occluder
octocopter
ocker
occulter
octameter
occipitoposterior
occlusor
occasioner
octuor
octopusher
Starts with OD3 words
odor
oddsmaker
odorizer
Starts with OE
2 words oedometer
oenometer
Starts with OF10 words
offer
officer
offender
officeholder
offeror
offerer
offspinner
offsider
officiator
offcutter
Starts with OG
1 words ogler
Starts with OH
1 words ohmmeter
Starts with OI
2 words oiler
oilpaper
Starts with OL8 words
oliver
oleander
oldster
oligomer
oleaster
olfactometer
oleorefractometer
oligochronometer
Starts with OM3 words
omer
ombrometer
omitter
Starts with ON10 words
onlooker
onliner
oncer
onager
oner
oneiromancer
oneyer
onsetter
onocentaur
oncometer
Starts with OP24 words
operator
opener
oppressor
optimizer
opposer
operagoer
opinionator
opter
opercular
opacifier
optocoupler
oppugner
optometer
ophthalmometer
opisometer
ophthalmodynamometer
ophthalmostatometer
ophthalmothermometer
opificer
ophiolater
opsiometer
ophthalmotonometer
ophthalmotropometer
ophthalmodiastimeter
Starts with OR20 words
order
organizer
orator
originator
orbiter
orchestrator
ornithopter
orderer
orienteer
ordainer
ormer
orthocenter
orientator
orienter
orthographer
ornithomimosaur
orthopter
orographer
ornithosaur
orometer
Starts with OS7 words
oscillator
ostler
osier
osmometer
ostracizer
ossifier
ostreodynamometer
Starts with OT
2 words other
otter
Starts with OU24 words
outer
outsider
outlier
ouster
outfielder
outlander
outfitter
outrigger
outpour
outrider
outsourcer
outliner
outswinger
outworlder
outliver
ouncer
outgoer
outputter
outworker
outrunner
outbacker
outvoter
ouvrier
outplacer
Starts with OV24 words
over
overseer
overthinker
overachiever
overcomer
oversharer
oversteer
overreacher
overspender
overnighter
overlander
overeater
overclocker
overstayer
overrider
ovipositor
overlooker
overdoer
oviraptor
overturner
overbidder
overruler
overthrower
overlayer
Starts with OW3 words
owner
ower
owler
Starts with OX7 words
oximeter
oxidizer
oxygenator
oxter
oxer
oxpecker
oxygenizer
Starts with OY4 words
oyster
oystercatcher
oyer
oysterer
Starts with OZ
1 words ozonizer