A random person who tags along with groups of people who he never usually interacts with. Occasionally he will speak up, and everyone in the group will look at him funny because no one is friends with him.
This term was created students 10 years ago to insult random people whose intrusive behavior resembled a science teacher named Mrs. Neff
A nerfstick is the tool by which a moderator or admin on an online forum strikes down on bad posts and posters. It is similar to, but has more uses than the ban hammer.
This use of the term seems to have originated from a moderator on the Secret World forums.
Example 1:
Sappho: "I have a very large nerf-stick at my disposal, and I'm not afraid to use it"
Example 2:
User: Where is the nerfstick Sappho? Are you getting soft on us?