Both couple and few can mean either a specific number (2 for couple, 3 for few) or an indeterminate small number. They are synonyms for the second usage.
I hadn't known a couple to mean more than 2, but the Cambridge dictionary does seem to agree[1].. however the Oxford Dictionaries site only seems to indicate only 2[2]. In this case, I'll update my correction ;)
You also instantly knew what the person meant by a couple because this is an extremely common usage. Oxford agrees as well, if you use their US dictionary [1].
In the US, "a couple" is synonymous for a "a few" or "several". One would say, "it'll take a couple of hours" or "I'll be away for a couple of days" and mean two or more. This might be specific to American English.
You could also have said that where you come from, couple means two people in a romantic relationship. This doesn't mean that it can't also have other definitions. Every US English dictionary I checked has "an indefinite small number" listed as one of the definitions, and that's a much more common usage in my (US) experience than using couple to mean exactly 2.
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Both couple and few can mean either a specific number (2 for couple, 3 for few) or an indeterminate small number. They are synonyms for the second usage.
I hadn't known a couple to mean more than 2, but the Cambridge dictionary does seem to agree[1].. however the Oxford Dictionaries site only seems to indicate only 2[2]. In this case, I'll update my correction ;)
[1](https://dictionary.cambridge.org/dictionary/english/couple)
[2](https://en.oxforddictionaries.com/definition/couple)
You also instantly knew what the person meant by a couple because this is an extremely common usage. Oxford agrees as well, if you use their US dictionary [1].
[1](https://en.oxforddictionaries.com/definition/us/couple)
In the US, "a couple" is synonymous for a "a few" or "several". One would say, "it'll take a couple of hours" or "I'll be away for a couple of days" and mean two or more. This might be specific to American English.
Where I come from (US) a couple means 2.
You could also have said that where you come from, couple means two people in a romantic relationship. This doesn't mean that it can't also have other definitions. Every US English dictionary I checked has "an indefinite small number" listed as one of the definitions, and that's a much more common usage in my (US) experience than using couple to mean exactly 2.
My interpretation has always been that a couple is approximately two, a few is approximately three, and several is ~5-7.