- on one' head
- on condition that
- offer up
- of the Dark Ages
- of benefit to
- overwhelming majority
- overdo it
- ocean liner
- over-anxious
- on one occasion
- opening ceremony
- overstate the case
- officially approve
- observe furtively
- opposable digit
- on a large scale
- on all sides of
- only remaining
- onward
- out of proportion to
- outflank
- oven-ready
- over and done with
- overwhelmed
- overwritten
- outbuilding
- overcrowding
- one's notice
- Old Dart
- overempha-size
- opportunity to be heard
- occa-sionally
- o'clock
- of benefit
- off the peg
- on show
- open one's heart
- open to
- optical
- old-age pensioners
- over-sentimental
- overjoy-ed
- organisation
- offer condolences to
- off course
- of influence
- open to the elements
- over-hastily
- obsession with
- osmosis
- out-think
- on a level
- occupants
- on the edge
- order someone around
- outrush rush
- outrge
- of greatest importance
- offen-sive
- ostentatiousness
- opportunity to purchase
- ordinary citizen
- offensiveness
- open to debate
- on one's stomach
- one and only
- oftend against
- olive black
- of low intelligence
- on the way up
- on the way to
- on the decline
- over-decorated
- open to discussion
- of current interest
- open on to
- olive-skinned
- outstretched
- oral history
- off track
- omnibus
- olden
- ominousness
- out for revenge
- one's cup of tea
- on the run
- offer a prayer
- opening remarks
- ousting
- out-spoken
- overloaded
- on bad terms
- overtax
- over-enthusiastic
- on the throne
- opposite number
- order around
- overtrusting
- official mark
- out of keeping with