[mmooss]

The word comes from Greek, θησαυρός - "a store, treasure, storehouse, treasury".

> The usage of "thesaurus" in English for a kind of book dates back to the first one by Peter Mark Roget in 1852

To nitpick, though of interest: The usage meaning a book of words organized by their senses indeed dates to Roget's use in 1852, as the parent comment says. An earlier usage is more generally a 'treasury' of knowledge (in book form): there was a Thesaurus Linguæ Romanæ et Britannicæ ... in 1565, a Thesaurus Linguæ Latinæ compendiarius ... in 1736, and John Stuart Mill in 1840 wrote about "A thesaurus of commonplaces for the discussion of questions."

Source: Oxford English Dictionary

[svat]

I did in fact look at Etymonline for "thesaurus" before I made my comment and therefore chose my words carefully, but not clearly enough. Yes there were books before Roget's that contained the word “thesaurus” (treasury) in their title, including at least one dictionary. But none of these earlier books caused the word “thesaurus” to start to mean a particular kind of book, which it does in English following Roget — and that kind of book is precisely one that contains synonyms and antonyms, and usually does not contain meanings or etymology. So the comment by folex remains weird — for one thing, it uses “stereotype” where “meaning” would be more appropriate.

[mmooss]

> Yes there were books before Roget's that contained the word “thesaurus” (treasury) in their title, including at least one dictionary. But none of these earlier books caused the word “thesaurus” to start to mean a particular kind of book ...

FWIW, OED has a separate sense for, "A ‘treasury’ or ‘storehouse’ of knowledge, as a dictionary, encyclopædia, or the like." Is that a particular kind of book or a general concept? I don't know.

Its usage extends past Roget - e.g., (1862) "In a complete thesaurus of any language, the etymology of every word should exhibit both its philology and its linguistics." and (1906) "This work is one of five thesauri published under the auspices of Kang Hsi, the second Emperor of the present dynasty."

And to be complete, a newer usage dates to 1957, "A classified list of terms, esp. key-words, in a particular field, for use in indexing and information retrieval.".

> I did in fact look at Etymonline

Etymonline is the admiral work of one person. If you can get access to the OED (and if you love etymology, etc., it's essential), you'll generally find much more, and much more reliable work done by teams of professional over ~150 years.

Etymonline's About page is incredible - I'm going to submit it:

https://www.etymonline.com/columns/post/bio

> the comment by folex remains weird — for one thing, it uses “stereotype” where “meaning” would be more appropriate.

Not weird at all - folex says they don't speak English natively. Stereotype makes sense in a way, but is not the word a native speaker would choose. I'm the same in some languages.

folex's question is maybe the most interesting part of the discussion.