OED, ok, let's try this online: expletive (OED): An oath or swear word. swear word (OED, advanced): synonym expletive, and gives examples in the Culture section. Specifically, in the fourth paragraph "The most common", the third sentence "The strongest swear words" list two words, the second of which was used for the fifth word of post.

PM has a nice notification system. So, it doesn't really matter when you reply, so long as you reply to the post of the person you want to see it.