Consider a $$t$$ distribution or the logistic distribution.  It’s unambiguous that these distributions are ‘heavy-tailed’, but a lot of courses use the terms ‘platykurtic’ and ‘leptokurtic’.  The former is from the Greek πλατύς, wide; the latter from the Greek λεπτός, light or thin.  I asked which was which. Again, you probably know this one, and again there’s a reasonable chance you’re wrong.  About 1/3 of respondents said ‘leptokurtic’ and 2/3 said ‘platykurtic’.