Castelar y Ripoll
biographical name
Cas·te·lar y Ri·poll ˌka-stə-ˈlär-ē-rē-ˈpȯlʸ 
Emilio 1832–1899 Spanish statesman and writer
- on appeal
- on approval
- on at
- on attachment
- on average
- on background
- on balance
- on base
- on behalf of
- on behalf of someone
- on bended knee
- on benefits
- on bluegrass
- on board
- on both counts
- on both sides
- on brand
- on call
- on camera
- on campus
- on closer inspection
- on cloud nine
- on command
- on commission
- on company time