You know what can kill a person without fail? Nope. I'm not talking about poison, or some other 'foolproof' method of dying.
A person truly is doomed to death when his mind is stifled.
With the rate of connections his brain is able to make diminishing towards zero;
With the electricity that should ideally be rushing freely through his neurons grinding to a staggered halt;
With each thought his brain is able to muster being thwarted, harassed and killed because it represents something in the living world which unnerves and frightens him;
When the exciting venture into the world of imagination/mental creativity only holds the inevitable caveat of the unleashing of a world of negativity better left untouched;
When all your thoughts you'd thought were your very own brainchild seem exposed as nasty seeds planted in your head by those who were able to advertise their agenda onto your impressionable, 'naive' mind;
When the only possible aftermath of any foray into conscious thought is the realisation of how thoroughly your brain has been drained, seeped of any chance at originality;
When you feel like all your precepts, ideas, tools for thinking are all a crumbled pile of obsolete rubble because you just never really are able to find that reality agrees with what you think of it;
When the slightest period of thought-flow that has successfully gone on uncontested is beset finally by the fear of having pushed your luck;
When you realise that the reason you can't get your brain to make the wasteful effort of thinking clearly is due to the strength of your belief that faced with an opportunity/scenario for the thought to have productive value, your power will desert you;
When you're certain that if someone told you that your life depended on you telling them your name, the one thing you could bet your bottom ruppee on not being able to recall is the word Mihir;
When you begin to feel that no amount of cognizable thought can be worth anything when reality is just lurking around the corner, licking its chops, waiting for you to make that turn so that it can kill that sorry little meagre confidence you dared to accumulate from thinking you'd understood something for real;
When the only thing that has made possible a flow of thought unobstructed for long enough as to enable a rant even as unimpressive as this is that the fact that everyone is asleep has empowered you to believe that no other mind can exert its influence on yours right now...
That person might as well be dead, for all the surviving he'd be capable of if a band of wayfaring robbers accosted him on his way to work, requiring of him to solve a simple arithmetic problem in exchange for an uncut throat.
If that isn't the definition of "death row", the phrase can only mean a situation in which Dumbledore and Harry merrily use oars to traverse the black inferus-filled lake in Voldemort's cave while singing 'Du Hast' on top of their voices.