Am I insane? IIN?

Greetings, Mr Pedant!

"'Eccentric', is probably a better descriptor."

I think you mean 'description'!

Definition of DESCRIPTOR: something (as a word or characteristic feature) that serves to describe or identify; especially: a word or phrase (as an index term) used to identify an item (as a subject or document) in an information retrieval system.

Or,

Descriptor may refer to some one who's name is shown(example - as on a bank statement - $200 credited to - "Descriptor")
file descriptor, an abstract key for accessing a file
index term, also known as a "descriptor" in information retrieval
molecular descriptor, which helps characterize a chemical compound
segment descriptor, used for memory addressing in x86 computer architectures
security descriptor, a Windows data structure containing security information
data descriptor, a software or hardware structure describing data

All the best!