meaning - Does "a couple" always mean two?

Today I said some event was a couple of weeks away. A native speaker from Australia corrected me and said, no it's at least three weeks away. What followed was a discussion as to whether a couple always means two, or if it can mean more than two.

What does a couple, in particular a couple of weeks, mean to a native speaker?

According to wiktionary:

1. Two partners in a romantic or sexual relationship.


2. Two of the same kind connected or considered together.


3. (informal) A small number.

According to OED:

1. two people or things of the same sort considered together:
   
   'a couple of girls were playing marbles'


2. [treated as singular or plural] two people who are married or otherwise closely associated romantically or sexually:
   'in three weeks the couple fell in love and became engaged'
   'a honeymoon couple'


3. [informal] An indefinite small number

Yet my colleague — a native speaker — insists that a couple never means three, although there can be a small error bar on the two. We asked one other native speaker who agrees with him, yet three non-native speakers point at the above-mentioned sources to claim they're wrong. But it's a bit tricky for non-native speakers to claim native speakers are wrong. Note that both native-speakers are from Australia/New Zealand.

Answer

Excellent question! The short (and rather unhelpful) answer is that while technically, "a couple" does in fact mean two, it is not always used that way in practice and if you ask several native speakers you're likely to get different responses.

"A couple", "a few", "several"... Words like this are used with various intent. In the particular case of "a couple of weeks" I'm (personally) likely to interpret that as 2-3 weeks away. In any other case where you use "a couple", it depends on the circumstances. I'll get a general idea of what you mean, but we won't necessarily have the same understanding of the situation.

Bob and Marie make a good couple.

Okay, that one's obvious. When you're talking about two people in a relationship as a "couple", clearly there are two of them.

I'll see you in a couple of weeks.

As I said before, this probably means 2, maybe 3 weeks (in my experience). I think this is probably the situation in which you're least likely to cause confusion, though obviously that's not always the case since someone corrected you!

These pretzels are delicious! Can I have a couple more?

Assuming these are snack-sized pretzels... Chances are I'm not just asking you for exactly two, right? Generally people use this to mean "give me some more of them" with "some" being indeterminate. The most common response would be to reach into the bag, grab whatever pretzels you would naturally get at a time, and give them to the person. Sometimes, just to be 'literal' and make a joke, I know people who will carefully count out two pretzels in this situation and give them to you. You'd give them a look, and then they'd give you more. So even native speakers are aware of this disparity, and can find humor in it.

If that's not enough, consider the following xkcd comic, where the author makes fun of the ambiguity of "a couple" and such words:

The author also adds mouseover text to his comic, which reads: "If things are too quiet, try asking a couple of friends whether "a couple" should always mean "two". As with the question of how many spaces should go after a period, it can turn acrimonious surprisingly fast unless all three of them agree." ;)

So there isn't a simple answer for you, I'm afraid, but the answer is it's all very dependent on who you're talking to and how they interpret the word. If your friend corrected you then he has a different interpretation--but that doesn't mean you were wrong!