1. The act of insulting someone via a reference to an embarrassing event in their past. The term was popularized by a scene in "Goodfellas" in which Billy Batts admonishes Tommy DeVito for his subservient childhood job by exclaiming "go home and get your f**kin shinebox."
2. Attacking someone for previous shameful actions, giving the impression said acts are indelible.
Mike opted to avoid attending his high school reunion, knowing they'd remember his loss of bladder control in gym class and be shineboxing him all night.