- ox
- ox-eyed
- ox-eyed daisy
- oxacillin
- oxalacetate
- oxalacetic acid
- oxalate
- oxalic acid
- Oxalidaceae
- oxalis
- Oxalis acetosella
- Oxalis caprina
- Oxalis cernua
- Oxalis corniculata
- Oxalis crenata
- Oxalis pes-caprae
- Oxalis tuberosa
- Oxalis violacea
- oxaloacetate
- oxaloacetic acid
- Oxandra
- Oxandra lanceolata
- oxaprozin
- oxazepam
- oxblood red
- oxbow
- oxbow lake
- Oxbridge
- oxcart
- oxen
- oxeye
- oxeye daisy
- Oxford
- Oxford English
- Oxford English Dictionary
- oxford gray
- oxford grey
- Oxford movement
- Oxford University
- oxford-gray
- oxford-grey
- oxheart
- oxheart cherry
- oxidant
- oxidase
- oxidate
- oxidation
- oxidation number
- oxidation state
- oxidation-reduction
- oxidation-reduction indicator
- oxidative
- oxidative phosphorylation
- oxide
- oxidisation
- oxidise
- oxidised
- oxidiser
- oxidizable
- oxidization
- oxidize
- oxidized
- oxidized LDL cholesterol
- oxidizer
- oxidizing agent
- oxidoreductase
- oxidoreduction
- oxime
- oximeter
- oxlip
- Oxonian
- oxtail
- oxtail soup
- oxtant
- oxtongue
- oxyacetylene
- oxyacetylene torch
- oxyacid
- Oxybelis
- oxybenzene
- oxybutyric acid
- oxycephaly
- Oxydendrum
- Oxydendrum arboreum
- oxygen
- oxygen acid
- oxygen debt
- oxygen deficit
- oxygen mask
- oxygenase
- oxygenate
- oxygenation
- oxygenise
- oxygenize
- oxyhaemoglobin
- oxyhemoglobin
- Oxylebius
- Oxylebius pictus
- oxymoron
- oxyopia
- oxyphenbutazone
- oxyphencyclimine
- oxytetracycline
- oxytetracycline hydrochloride
- oxytocic
- oxytocic drug
- oxytocin
- oxytone
- Oxytropis
- Oxytropis lambertii
- Oxyura
- Oxyura jamaicensis
- Oxyuranus
- Oxyuranus scutellatus
- Oxyuridae