[back-fORmation from hairy] 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!")