Full Idea
In the Aristotelian tradition, a 'nominal' definition is a pseudo-definition that identifies the members of the species or genus, but fails to capture the essence, e.g. 'man is the featherless biped'.
Gist of Idea
'Nominal' definitions identify things, but fail to give their essence
Source
Jan-Erik Jones (Real Essence [2012], §2)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.4
A Reaction
You can 'individuate' an object as 'the only object in that drawer', while revealing nothing about it. So what must a definition do, in addition to picking something out uniquely?