- of interest
- of little value
- on second thoughts
- occultism
- obsessive about
- on the bread line
- ouster
- of means
- overprotective
- order to
- orb-shaped
- oaths
- other man
- on the job
- on the road to recovery
- on the edge of one's seat
- outbursts
- one's kip
- off-centre
- obeying
- on one's last legs
- owners
- obsecration
- overplayed
- on the same wavelength
- over-brim
- over-wrought
- on the doorstep
- odiousness
- ovenproof
- opress
- open to attack
- over-critical
- on the stocks
- old lag
- oblate
- ordinal number
- objecting
- overacted
- overset
- out of humour
- one-on-one
- other than
- overfamiliar
- ordinances
- overcrowd
- osculation
- offentimes
- on pins and needles
- old stager
- on full alert
- overlooked
- on the qui vive
- overdose
- on the outs
- on welfare
- on the barrelhead
- or thereabouts
- one's cross to bear
- of importance
- of substance
- overhadow
- owner-occupancy
- oojamaflip
- of consequence
- outside of
- overwight
- offprint
- on the skew
- one's portion
- out of sort
- overemphasized
- offcuts
- on the blink
- over and above that
- on the wallaby track
- olde worlde
- one's salad days
- over-dramatized
- occurrences
- out-of-towner
- off target
- of good report
- on the stroke of something
- obligingly
- old wives' tales
- overkill
- outer limits
- out of the ark
- out of love
- overload oneself
- overelaborate
- outbalance
- overman
- oojah
- owner-occupier
- oojamafflip
- oil the wheels of
- of ample proportions
- outstan-ding