hair [back-formation from hairy] n. The complications that make something hairy. "Decoding TECO commands requires a certain amount of hair." Often seen in the phrase `infinite hair', which connotes extreme complexity. Also in `hairiferous' (tending to promote hair growth): "GNUMACS elisp encourages lusers to write complex editing modes." "Yeah, it's pretty hairiferous all right." (or just: "Hair squared!")