Countable Nouns Starting with O and Containing OP

This list gathers 266 English countable nouns starting with O and containing OP, such as Open, Operation, Opportunity, Opinion, Option, Opening and Opposition. Use the sorting controls below to organize entries by length, or consult our noun grammar guide to review singular and plural count rules.

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Starts with OC11 words
octopus
octocopter
octopod
octopoid
octoploid
occipitoposterior
octopodan
ocnophil
ochlophobic
ochlophobiac
octopusher
Starts with OD5 words
odontophore
odontophobia
odorophore
odontophoran
odontopteryx
Starts with OE
2 words
oenophile
oenophilist
Starts with OL5 words
oligopoly
oligopeptide
oligopolist
oligopsony
olfactophobia
Starts with OM6 words
ombrophile
omophorion
omoplate
ommatophore
ombrophobe
omentosplenopexy
Starts with ON5 words
onomatopoeia
onomatopoiesis
onychophoran
onychophagist
oneiroscopist
Starts with OO8 words
oops
oop
oophorectomy
oophorosalpingectomy
oophyte
oophoron
oophorhysterectomy
oophorocystectomy
Starts with OP24 words
open
operation
opportunity
opinion
option
opening
opposite
opposition
opponent
operator
opera
optional
optimization
oppression
opioid
optics
opaque
op
optimum
opener
operative
opacity
optimist
opiate
Starts with OR24 words
orthopedist
organophosphate
ornithopter
organophosphorus
oropharynx
orthopod
orthophosphate
ornithopod
orlop
orthopraxy
orthoptist
orthopteran
orthopyroxene
oropendola
ornithophobia
orthopedy
orthopteroid
orthopter
orthoscope
orthopterist
orthopteron
orthopterologist
orthoprism
orthopsychiatrist
Starts with OS13 words
oscilloscope
osteopathy
osteopath
osteophyte
osteopetrosis
osmophobia
osteoplasty
osteoarthropathy
osmophobic
osteopathist
osteochondropathy
osteochondrophyte
ostreophage
Starts with OT3 words
otoscope
otoplasty
otoscopy
Starts with OU6 words
outcrop
outcropping
outrope
outroper
outroop
outrooper
Starts with OV5 words
overdevelopment
overcrop
overoptimist
overproportion
overhope
Starts with OX
1 words
oxytrope

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ABCDEFGHIJKLMNOPQRSTUVWXYZ
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