- oojah
- once-over
- out of step with
- of ample proportions
- on one's toe
- outstan-ding
- oldsters
- overelaborate
- outer limit
- overload oneself
- overman
- owner-occupier
- oddball
- on the dot of something
- oil the wheels of
- out of the ark
- oldie
- of no fixed address
- out of true
- over the fence
- on the fritz
- on the way out
- overpopulated
- on the go
- oppo. china
- overfamili-arity
- oddness
- on the understanding that
- on one's lonesome
- oppo
- one's dole
- on one's beam-ends
- oomph
- one' cards
- out of hand
- orthoepy
- osteopathy
- 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
- offsider
- overhasty
- on the ark
- overseeing
- out of control
- on the fence
- opinions
- on the bread-line
- outspokenly
- opaline
- on one's Jack Jones
- of no account
- oxbow
- omitting
- of moment
- oil someone's palm
- on the money. exclamation precisely
- on that account
- overstep
- osculate
- one in a million
- overlong
- openhandedness
- over the hill
- one-off
- on one's Pat Malone
- omnium gatherum
- on hold
- out of one's depth
- okay
- orotund. bombastic
- on the subject of
- overpitch
- on cloud seven
- oik
- oldster
- old womanish
- off center
- on the mark
- over-adventurous
- outstandingly
- out of whack
- outflowing
- on the rampage
- one-liners
- ombudsman
- overexcited
- on the top of the world
- on the breadline