- most open letter
- most open market
- most open minded
- most open mouthed
- most open pit
- most open source
- most out and out
- most out of the way
- most out of town
- most over the counter
- most owner occupied
- most paid up
- most paper cutting
- most paper pushing
- most paper thin
- most part time
- most party line
- most party walled
- most passive aggressive
- most pay as you go
- most pay per view
- most pear shaped
- most peglegged
- most pennsylvania dutch
- most pent up