an individual whose performance in a given area or success at specific endeavors is highly impressive, unique and/or admirable; this appellation is generally used sparingly, although the term is sometimes used frivolously to express purportedly extreme gratitude, as in: “Thanks for picking up my mail for me, you’re a rock star”; persons so designated are expected to have markedly different career trajectories in relation to their peers, although, as with many in the field of music from which the term derives, they may similarly end up flaming out in ruinous ways