Full Idea
A noun [for Aristotle] is proper when it has but a single sense. Better, it is only in this case that it is properly a noun. Univocity is the essence, or better, the telos of language.
Clarification
'Univocity' is having only a single meaning
Gist of Idea
For Aristotle all proper nouns must have a single sense, which is the purpose of language
Source
Jacques Derrida (works [1990]), quoted by Simon Glendinning - Derrida: A Very Short Introduction 5
Book Reference
Glendinning,Simon: 'Derrida: a Very Short Intro' [OUP 2011], p.55
A Reaction
[no ref given] His target seem to be Aristotelian definition, and also formal logic, which usually needs unambiguous meanings. {I'm puzzled that he thinks 'telos' is simply better than 'essence', since it is quite different].