- overwrite
- overspend
- over-sensational
- obliviousness
- outturn
- opposers
- on the block
- off-course
- overarching
- open-work
- outmost
- observation of
- or rather
- oviform
- outfits
- oiled
- on level with
- others
- on numerous occasions
- ocean-going
- once and for all
- opening statement
- out of harmony
- out of line
- one's advancing years
- of the wall
- on one' own
- overplay
- on the map
- ornithologist
- of no value
- on the quiet
- orbshaped
- one's career
- overdraw
- oppugnant
- out of shape
- only now
- on the strength of
- over-wrouht
- out of touch with reality
- one of a kind
- oddment
- on the attack
- outst-anding
- on offer
- off the top of one's head
- outer edge
- one-party
- odysseys
- opencast mine
- open to doubt
- only to be expected
- orison
- orient oneself
- occultation
- oral tradition
- oceanic
- on the bias
- outstanding payment
- obsolescence
- otherworldly
- of yore
- old codger
- of the utmost importance
- offal
- overtired
- outpace
- overvalue
- old lady
- of unsound mind
- on everyone's lips
- outback
- overburden
- on record
- objectives
- old-maidish
- ovid
- on the assumption that
- overnighter
- on the lookout
- of the order of
- open one's mouth
- one-eighty
- on the same wave-length
- on the never-never
- omitted
- old-world
- obscenities
- old saw
- oriel
- occupied with
- occupier
- of the old school
- one after the other
- on the wagon
- one's cards
- on the right lines
- on a level with
- of value