- on the distaff side
- open to suggestions
- other ranks
- out of position
- out-of-doors
- outlying districts
- once-a-year
- outbuilding
- openness
- offer one's services
- overcrowding
- orthodontist
- one's notice
- of bad reputation
- Old Dart
- overempha-size
- operations
- overtiredness
- open wide
- opportunity to be heard
- of vital importance
- of ill repute
- overtime
- occa-sionally
- official residence
- object strongly to
- one only
- ophidian
- o'clock
- of benefit
- off the peg
- olive green
- on show
- on the other hand
- on the top
- open one's heart
- open to
- optical
- out of condition
- of low intelligence
- one-to-one
- one-rous
- occupants
- on the sly
- on good terms
- offcial
- old clothes
- of current interest
- one-use
- off track
- ozone-friendly
- over-sentimental
- opportunity to purchase
- ominousness
- overfeed
- owed
- overestimate one's ability
- over-scrupulous
- outer ear
- open to discussion
- off one's guard
- on the way up
- on one side
- oftend against
- of greatest significance
- officiate at
- oblational
- optic
- overtures
- on the edge of
- occur in turn
- opponent in law
- outpatients' department
- overjoy-ed
- omnivo-rant
- of influence
- of unknown name
- out of a job
- outermost
- of course not
- overambitious
- other possibility
- of one's on volition
- offer a prayer
- on every occasion
- oversimple
- of incalculable value
- opening remarks
- over-elaborate
- of considerable importance
- occidental
- outward show
- other side
- out dated
- on the alert
- objectless
- object of ridicule
- out of keeping with
- oblong
- overeating