Maybe, from the statement, "Low-key" is a somewhat common label for this word-something is being very Strongest matches marked as not hitting the obvious addresses and not pulling as much attention. It is that frankly such is used to express feelings and opinions or perhaps situations usually kept on the down-low or not discussed directly. It is a way to express feelings without much pomp or show, straight up, in an informal way, where too much fuss may feel like bad rhythm.