- on one's toes
- obstructions
- old salt
- on benefit
- one-liner
- of concern
- of the same standard as
- overrunning
- on the doorstep of
- ovoid
- of little merit
- oil painting
- on sale
- on dit
- over-dramatize
- overhauling
- over indulge
- opt for
- on the q.t
- on guard
- opened out
- out of danger
- old fangled
- orderliness
- originate from
- on occasions
- ottoman
- of service
- on holiday
- obovate
- one's time of the month
- open-pit mine
- on the ground
- oyster mushroom
- offences
- outfox
- on tenterhooks
- on one's feet
- offish
- of old
- offices
- obscured
- obtained
- opt or plumb for
- on the wrong track
- one's pit
- obsessive-compulsive
- occultist
- object of virtu
- on the contrary
- outrageously
- on the lam
- object to
- old boot
- over-whelm
- overfill
- on the verge of
- old-timer
- overprotectiveness
- one's advanced years
- outplay
- obscurely
- out of tune
- obeying
- over-peopled
- obstructed
- on remand
- outbursts
- over-bearing
- once upon a time
- other man
- one's declining years
- outlawing
- of little value
- offcomer
- oxidize
- obesity
- on the edge of one's seat
- orders
- one's kip
- opposer
- on the bottom
- oversized
- off-centre
- on the road to recovery
- on the job
- on second thoughts
- on the dole
- originate in
- ouster
- on the bread line
- obsessive about
- occultism
- obliteration
- obesity corpulence
- outlawed
- off-the-cuff
- overprotective
- out of keeping
- order to