A Definition (n.) of an individual may always be overthrown, as the definition-monger must know.
A Definition (n.) is not just a word paired with a formula — otherwise even the Iliad would be a definition.
A Definition (n.) collapses into its last difference once done properly: 'animal with feet, two-footed' already contains the rest.
A Definition (n.) is a sort of number: add or remove the smallest part and it is no longer the same.
A Definition (n.) done superficially confuses being double with being 2, merely because 2 is the first thing that is double.
A Definition (n.) breaks down on snubness: snubness is concavity-in-a-nose, so 'snub nose' says 'concave-nose nose' — and the regress of noses never ends.
A Definition (n.) is a 'long rigmarole,' said the school of Antisthenes: one cannot say what silver is, only that it is like tin.
A Definition (n.) refers not to words but to the things themselves. It does not concern what the word 'tiger' means, but rather tells us what it is to be a tiger, what a tiger is said to be in respect to itself.
A Definition (n.) is best when it has two parts: first, it assigns the object in question to a class or group whose general characteristics are also its own (i.e. man is an animal), and secondly, it indicates wherein the object differs from all the other members in its class (i.e. man is a rational animal).