What is "tireder"

Usage examples of "tireder".

Cordelia thought she had never seen a tireder looking human being, but then, she had no mirror.

Marie LeGarde tried to smile at me, but it was a pathetic effort, and she looked ten years older than she had on the previous night: she was one of the few with a sleeping-bag, but even so she must have passed a miserable six hours, and there is nothing so exhausting to the human body as uncontrollable night-long shivering, a vicious circle in which the more one shivers the tireder one becomes, and the tireder the less resistance to cold and hence the more shivering.