A word used to make up for gaps in conversation, when the speaker is not certain what they want to say next. Can be very annoying if used excessively.
Prime examples include: er, um, erm, and uh
Person 1: What's a black hole?
Person 2: Black holes are...um...they're uh...black holes, they...erm...er...
Person 1: You have no fucking clue, do you? You're just using filler words now.
An electronic file folder or other compiling containing unflattering videos, photos, Snapchats, texts, etc. of a friend for future roast, embarrassment, or blackmail.
A (generally) teen-age boy who spends the majority of his time masturbating into a tube sock. Sock fillers tend to be socially awkward, often standing slack-jawed while in the presence of their female classmates.