on that score
on the air
on the alert
on the average
on the cheap
on the contrary
on the defensive
on the eve
on the fly
on the fritz
on the grounds of
on the house
on the inside
on the instant
on the job
on the level
on the market
on the mend
on the nose
on the occasion of
on the off chance
on the one hand
on the other hand
on the outside
on the phone