That is a completely different usage of the word as far as I'm concerned, like confusing nut ( and bolt) with nut (from a tree), in this case 'a couple' like two people in a relationship implies a link, like they are coupled. A couple of apples does not imply any link, it just means some small number.
It's not a completely different usage, it's literally the same usage, because couple means two. Thus, a couple (of people) means two people, just as a couple of apples means two apples. Being coupled also derives from the original meaning, two being bonded as one object (see also: coupling). These are all variations of the same word, etymologically. In contrast, nut from a car versus nut from a tree are wholly different both in meaning.
No - common usage is clearly more than 2. In the context of relationships I completely agree because no one says "They are a two".
But when you are in the context of quantity, "a couple" is a quicker way of saying "between 2 and 3/4/5" .
There are no "rules" in English, only conventions. It is a product of whoever speaks it and whatever they bring with them, and as such is forever changing and evolving without any control or authority.
Isn't that basically what we are debating about? It is clear that "common" usage differs substantially where while some use your definition, others mean mine. And anyway, it is also clear that, based on many dictionaries, the original definition at least always meant two.
I did not cite Latin, for the record, looks like you're thinking of the other person in this thread. But yes, words definitely have definitions, whether one wants to debate their meanings is a different matter.
