OSI & OSD: the same thing (and no longer even as useful as they were?)
The OSI are a useful (but declining in usefulness, btw - see SPDX, below) collection of known licences, but they do NOT define "Open Source" - they define what they have based their list upon, that is the sum total of it.
Once you have invoked the OSI list, any reputable report should make it clear that the OSD is *not* some separate measure of openness but is merely the document the OSI themselves drafted (cribbing from Debian, but it is now a distinct document) and use to qualify who will join their list.
Even this Register article may (will!) mislead (by the uncritical quoting of Erica Brescia) the less knowledgeable into believing that this LLaMa licence has failed on two independent counts, not just one.
Whether you wish to take their definition on as your personal definition of OSS, in all of its particulars, without fault or dispute - that is your privilege, but it does not force anyone else to do the same.
There was a LOT of shouting when the OSI was created, because it was seen to be making claims on behalf of software authors it had never spoken to (as in, the vast, vast majority of them - have *you* had your letter from the OSI, introducing itself and wondering if you'd like to have them represent you?). That was never settled (there was no vote): the OSI does NOT have any power over "open source" as a whole or as a concept, no matter what it claims. Generally, the shouting has died down - except on the OSI's own front page - and we get on with things without really giving them much thought, day to day.
The OSI was useful as a repository of well-known licences, but that is all it has ever done: it has not, and to this day, does not offer anything useful in terms of analysis of the applicability of material under one licence or the next (go look up its copy of GPL2 and of MIT licences: note the (total absence of) links to their careful discussion of the pitfalls of one against the other).
Nowadays, I would point people at the SPDX list in preference to the OSI list: SPDX ids are what you want to quote these days and they provide a tick against OSI, if that is useful to you, as well as the FSF "free/libre" acceptance, which OSI can not be bothered to do. Any system to help you judge between, juggle responsibilities of, the various licences (such as creating you Software BOM) is going to use SPDX notation, so best to get straight to it.
BTW the OSI claim "The “open source” label was created at a strategy session held on February 3rd, 1998 in Palo Alto, California, shortly after the announcement of the release of the Netscape source code." Bollocks. Open source as a phrase was in use before then. Even Wikipedia agrees. The OSI has a very grandiose view of itself, very suitable for articles of this sort.