What is (a) To thicken and shorten, as a heated piece of iron, by hammering on the end. (b) To shorten (a tire) in the process of resetting, originally by cutting it and hammering on the ends called?

upset — (a) To thicken and shorten, as a heated piece of iron, by hammering on the end. (b) To shorten (a tire) in the process of resetting, originally by cutting it and hammering on the ends. (Webster's 1913.)