- on horseback
- official killer
- ostenta-tious
- of no consequence
- one at a time
- order someone about
- observe the rules
- olive green
- on show
- of ill repute
- o'clock
- opulently
- overview
- over-suspicious
- on reflection
- order back
- of vital importance
- object strongly to
- one only
- other ranks
- out-of-doors
- outlying districts
- out of condition
- of long ago
- once-a-year
- outbuilding
- openness
- orga-nize
- offer one's services
- old fogy
- overcrowding
- ossified
- outgoing person
- on the distaff side
- one's notice
- open to suggestions
- open one's heart
- on the far side of
- Old Dart
- overempha-size
- opportunity to be heard
- operations
- overtiredness
- out of position
- open wide
- on every side
- one step at a time
- ordeals
- orchestration
- over talk round
- of bad reputation
- overdo it
- orthodontist
- ocean liner
- overstate the case
- observe furtively
- only remaining
- onward
- over-anxious
- officially approve
- on one occasion
- official approval
- official list
- overspill
- overstated
- occur with
- overseas
- offertory
- obsessional
- obtain by force
- ophidian
- on condition that
- offer up
- official residence
- overwhelming majority
- occur to
- overstretch
- oesophagus
- openwork
- opening ceremony
- overlap
- onwards
- one of
- once a year
- objecti-vity
- one's regrets
- objec t
- on to the shore
- officialdom
- on top form
- ornaments
- opposable digit
- on standby
- obli-gation
- on the top
- on one' head
- open one's heart to
- on the other hand
- of the time
- overwhelmed