O字母開頭的單詞或詞組(第20頁)：
- overflow nipples
- outstanding check
- oxidize
- Oxford
- O antigen
- odometer
- old-money
- off-track
- on earth
- on the verge of
- oneself
- Obadiah
- or otherwise
- on-position
- open sb.'s eyes to
- optical device
- outskirts
- other income
- outgoing call
- outlying
- overbite
- overbalance
- oomph
- offhand
- off-peak
- offset binary code
- offspring
- one's cup of tea
- Olympic Games
- onycho-
- open wide
- ovalbumin
- outgas
- overhead
- on principle
- offered load
- of
- Obermayer's test
- objectiveness
- objectivity
- off-balance
- omasum