- over-appreciative
- owing someone a debt of gratitude
- one or two
- old boy
- occupy oneself
- observation of
- outmost
- of immeasurable worth
- on the slate
- one after another
- other woman
- outstretch
- open to change
- ordered
- on numerous occasions
- over-elaborateness
- on an equal footing
- outrageousness
- obstacles
- observed
- old saw
- obscenities
- otherworldly
- one's cards
- oceanic
- on the wagon
- one-eighty
- one after the other
- on the strength of
- occupier
- old-maidish
- obsolescence
- of the old school
- once and for all
- open one's mouth
- on the assumption that
- old codger
- orient oneself
- on the never-never
- on offer
- oriel
- overplay
- off the top of one's head
- of yore
- on the bias
- one's advancing years
- orbshaped
- occupied with
- oppugnant
- out of line
- overvalue
- over-wrouht
- opening statement
- one of a kind
- outstanding payment
- of the utmost importance
- overtired
- one-party
- of no value
- on the map
- old lady
- old-world
- ornithologist
- outpace
- out of touch with reality
- omitted
- on the same wave-length
- objectives
- out of shape
- on the quiet
- one's career
- oddment
- of the wall
- on the attack
- odysseys
- opencast mine
- open to doubt
- only to be expected
- orison
- occultation
- oral tradition
- offal
- on one' own
- of unsound mind
- on everyone's lips
- outback
- overburden
- only now
- on record
- ovid
- overnighter
- on the lookout
- of the order of
- outer edge
- out of harmony
- on the right lines
- on a level with
- outst-anding
- overdraw
- of value