- oscar wilde
- ordered tree
- ornithophilous
- odocoileus virginianus
- of no significance
- oil of theobroma
- oil theobroma
- oblique ridge
- oblique popliteal ligament
- or circuit
- ophthalmodiastimeter
- one's arms to be restless to fight
- one upmanship
- orbital border
- oesophagectomy
- oxyuriasis
- oxidase reagent
- orbito_ethmoidal cell
- orbital index
- oesophago_bronchial fistula
- orbitofrontal area
- out spool area
- oesophagogastric cooling
- oribital sulcus
- occipital point
- occipital cortical stimulation
- oesophagogastrectomy
- oxypropionic acid
- outgun
- over the course of
- occipital lymph node
- oesophagojejunostomy
- occipital curvature angle
- occipital cutvature angle
- oesophagectasia
- occipitotemporal gyrus
- oesophagitis
- occipital sinus
- occipital convolution
- open mind to
- occipital suture
- occipito_anterior position
- outmatch
- outperform
- on a par with
- one who extends cooperation
- on looker
- onlooker
- one whose profession is to remove wax from the ears
- owning or having a business