On demand audio – The act of streaming or turning audio into digital data and transmitting it over the Internet.
On the beach – A radio industry term for being unemployed.
Open mike – A mike which is live, on at the given moment.
Obscene language – A term that is most often used in a legal context to describe expressions (words, images, actions) that offend the prevalent sexual morality of the time. It can simply be used to mean profanity, or it can mean anything taboo, indecent, abhorrent, or disgusting. (Latin: obscenus, meaning “foul, repulsive, detestable.)