- on-the-part-of
- on the part of part
- on the part of sb
- on the part of sb/on sb's part
- on the part on part
- on the phone
- on the piss
- on-the-point-of
- on the prowl
- on the pull
- on the quiet
- on the qui vive
- on the rack
- on the radar screen
- on the razor's edge
- on the razzle
- on the rebound
- on the receiving end
- on the right side of 40
- on the right side of 40, 50, etc.
- on the right side of 50
- on the right track
- on the right/wrong side of 40, 50, etc.
- on the right/wrong track
- on the road