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