bib: Very excellent question I too have pondered. In one's choice of a synonym, it's not the length but the familiarity

It will fall in one of three levels: 1) Everyday speech; basic English: "laugh" 2) Less often used but more expressive and likely to be understood by nearly everyone: "guffaw" 3)Snooty: "cachinnation"

Of course 3) is more likely to be longer than 1), as above. One should cultivate one's vocabulary to more often use type 2)when it better expresses the idea, though not to excess

dalehileman