- oojah
- overfamili-arity
- on one's toe
- outspokenness
- owner-occupier
- of distinction
- out of love
- off Broadway
- one's better half
- on the mend
- on the eve of
- oldsters
- oppo. china
- out of step with
- outer limit
- oddball
- oldie
- out of true
- over the fence
- once-over
- overman
- on the way out
- oil the wheels of
- of no fixed address
- on the fritz
- out of the ark
- out-standing
- oppo
- on one's lonesome
- one' cards
- outrival
- on the understanding that
- object of the exercise
- outer reaches
- of the highest quality superlative
- one-horse
- other half
- oomph
- on this account
- of little account
- on one's beam-ends
- orthoepy
- oddness
- osteopathy
- outperform
- one's dole
- otiose
- over-effusive
- out of hand
- overlooking
- offcut
- on that account
- on the bread-line
- out of control
- overstep
- oxbow
- opaline
- overhasty
- on the fence
- overseeing
- of no account
- on the money. exclamation precisely
- offsider
- outspokenly
- of moment
- on one's Jack Jones
- omitting
- oil someone's palm
- on the ark
- osculate
- opinions
- over the hill
- openhandedness
- overlong
- okay
- one-off
- one in a million
- on one's Pat Malone
- overpitch
- out of one's depth
- omnium gatherum
- orotund. bombastic
- on the subject of
- on hold
- oik
- over-adventurous
- on the rampage
- on us
- off center
- outflowing
- oldster
- old womanish
- out of whack
- on the top of the world
- ombudsman
- on cloud seven
- on the breadline
- outstandingly
- overexcited
- one-liners