I can't remember if the exact words are spoken, but there's a scene in one of the first two episodes where a man almost commits suicide (but is talked out of it by the male lead).
In the subtitles on Viki, anyway, not in the audio. Around episode 3 or 4. When the male lead sees a bunch of clients, he reenacts one of them verbally abusing people, and uses this word. The male lead is angry about the verbal abuse and will not represent the client.