Let me get this straight, your word or the word, illuminous, was declared obsolete in the midSeventeenth Century.

Wha Ive read yes

Who determines if a word should be obsolete?

I cant speak for the Seventeenth Century but currently lexicographers dictionary editors are the authority

                                                                                                                I will say this however  words are labeled obsolete archaic old-fashioned rather than deleted

Like good oldfashioned liveryless

                                     Livery  Horses  Without horses   Liveryless

It is an obsolete word

    And why do you know that?

I read the dictionary dictionaries  I own many different dictionaries published in the Thirties an forward

Why?

Words

         Fascinating as shithave always been to me

I wish languages came easy

                                  They have not do not

    Whell, you should realise ya just shot me down.

Shot you down  How

I thought if there was an Obsolete Committee, that’d be a committee I wouldn’t mind heading.

Thas funny

               You actually made a joke

I did didn’t I?

    Don let it go to your head

                                  Even a broken clock is right twice a day

427preferred,  Sunday,  5  1. 25

1613,  Monday – Remember January 6, 2021   2025

https://qz.com/1061782/the-complex-process-that-dictionaries-use-to-decide-which-words-are-obsolete#:~:text=That%20said%2C%20lexicographers%20do%20have,out%2Dof%2Duse%20word.