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