- on a grand scale
- over the top
- over-trustful
- occurring recently
- overspread
- overturned
- on impulse
- overplaying
- of high standing
- overdrawn
- open to the weather
- oxygenate
- older
- obedience
- one and the same
- ooze out
- offer one's life
- odds-on
- overdraft
- of great consequence
- octad
- oneself
- open-mindedness
- of prime importance
- obtrude
- of use
- on account
- overhanging
- old-age pensioner
- over-reach
- obtaining
- on a weekly basis
- on the outskirts
- on the side of
- offer prayers
- opera star
- oozing
- on an incline
- one's bag
- operte
- open to error
- oil
- outburst of rage
- OAPs
- overuse
- out of debt
- offer suggestions
- observer viewers audience
- offer for sale
- on one's side
- on the grapevine
- onetime
- out of contact with
- open to argument
- obscuring
- opacity
- of the same opinion
- only just
- outage
- overbright
- on the farther side of
- overeach
- overprotected
- on one's front
- on the spur of the moment
- on top of
- of sound mind
- overhear
- overestimate
- oilcan
- octaves
- on the road to
- occur in rotation
- overtly
- obverse
- ordnance depot
- over-emotional
- of great import
- over-embroider
- operable
- outcasts
- oversweet
- outward form
- on special offer
- on the best of terms
- objections
- overshoot
- overindulge oneself
- onlookers
- object of virtue
- open the door to
- opportuneness
- officer of the law
- old wives' tale
- out of the limelight
- out-turn
- over-priced
- opposite pole
- own up to
- opportunely