The word "fool". Try it out. When someone disappoints you or does something stupid, throw the word out. C'mon, give it some gusto. You fool! You...(deep breath, now) FOOL! Got the hang of it yet? No? It just sounds silly in real life? Well, get used to it, because fiction? Fiction loves this word. It's the ultimate insult. Every villain, or at least nearly so, uses it, every hero with a hasty friend uses it... hell, if we were to list every example we could find, that would take up too much webspace. It's so common. Only really prominent examples should be listed. The term's use is much like the existence of crocodilians - both have existed for quite some time, are known to snap at many a living thing around them, and show little to no overall signs of ever disappearing.
During the Rennaissance "fool" was a very powerful insult when referring to a man; women and children were thought of as inherently foolish (and it was only a mild insult when applied to them) while adult men were supposed to be distinct. To call one a "fool" was to question his manhood and ability to manage his life and household, and it was sparking full-scale fistfights up until the 1650s. Professional fools such as jesters were not regarded as respectable adult men but as amusing Manchildren, with their costumes made to evoke the clothes of children and often carrying noisy staffs suggesting baby's rattles.
