Which is, of course, nonsense; adieu is from French, and the fact that the French word is in its turn from a Latin phrase is a separate issue.
I don’t agree that it’s a separate issue when discussing word origins; it might be when discussing from where words were borrowed, but not when discussing their origins.
or·i·gin [awr-i-jin, or-] Show IPA
something from which anything arises or is derived; source; fountainhead: to follow a stream to its origin.
rise or derivation from a particular source: the origin of a word.
the first stage of existence; beginning: the origin of Quakerism in America.
Therefore, if we follow the history of adieu from English to its source, it would be French, but the origin is Latin(as far as we know). English could not have borrowed it from French, without French having borrowed it from Latin.
Online Etymology Dictionary
c.1400, “ancestry, race,” from Old French origine “origin, race,” and directly from Latin originem (nominative origo) “a rise, commencement, beginning, source; descent, lineage, birth,” from stem of oriri “to rise, become visible, appear” (see orchestra).
It would be nonsensical to lump French words of Latin origin borrowed into English from French, like route, issue and annoying, with words taken directly from Latin such as separate, phrase and origin.
I think nonsensical is an overstatement. Again, when discussing origin, as the word is defined, one seeks the source. I understand that in many cases the source might be ambiguous and as Dave said:” It’s turtles all the way down, and where you stop tracing is an arbitrary decision.(Although after a little bit of evidence drys up. WE really can’t trace words further than Old English or Latin.” ]
It’s also not even true to say that Latin is the ultimate origin of any of these words, PIE being that, as far as we can tell.
I never stated that Latin is the ultimate origin; I was submitting an idea and seeking edification.
Many of the most common polysyllabic English words are of Latin origin, through the medium of Old French.