Collins English Dictionary: English Words Starting With “O”
- on the fly
- on the foundation
- on the front foot
- on the go
- on the heavy side
- on the hoof
- on the hook
- on the hop
- on the horizon
- on the horns of a dilemma
- on the house
- on the improve
- on the increase
- on the instant
- on the job
- on the jump
- on the knocker
- on the lam
- on the level
- on the loose
- on the make
- on the market
- on the mend
- on the money
- on the move
- on the nail
- on the nod
- on the nose
- on the off chance
- on the off-chance
- on the outer
- on the panel
- on the parish
- on the part of
- on the pig's back
- on the piss
- on the point of
- on the port bow
- on the prowl
- on the q.t.
- on the qui vive
- on the quiet
- on the rampage
- on the razzle
- on the rebound
- on the right foot
- on the road
- on the rocks
- on the ropes
- on the run
- on the safe side