As Amos was a bit coy about giving us the meaning of "estimate" here it is:

estimate - noun
a guess of what the size, value, amount, cost, etc. of something might be

estimate - verb
to guess the cost, size, value, etc. of something

So what you and Bobert are basing your claim that "Upwards of a million Iraqs have now been killed" is a GUESS. Which if any had bothered to read The Lancet Article would have been obvious as in thet article the introduction clearly stated that "Iraqi civilians MAY HAVE died".

If you are going to make statements on numbers of fatalities the least you can do is base them on something better than a GUESS.