Is "a half dozen" necessarily 6, or can it be 5-7?

In my answer to a question on the SF & Fantasy stack, I assumed that "half a dozen" is imprecise enough to mean anywhere from 5 to 7. Another user challenged that assumption and stated that since a dozen is 12, a half dozen is necessarily 6 and nothing else.

In the answer to a similar question, it is said that

Dozen is quite flexible when it is pluralized.

Does half count as a pluralisation? Can "half a dozen" mean anywhere from 5 to 7, or can it only be 6?

Solution 1:

The most likely answer is: It Depends.

If I go to the store and buy half a dozen eggs, half a dozen donuts, and half a dozen muffins, I'm going to be extremely annoyed if when I get home I find only 5 eggs, 5 donuts, and 5 muffins in the packages.

On the other hand, if I am complaining about the length of the checkout line, I might say "look at this! half a dozen people waiting and they're not opening a new lane," when in fact there are only 4 people, including myself and the person who's actually being served. I am not doing a precise count, only a quick (and most likely exaggerated for the sake of complaining) estimation.

Similarly, at the party when I ask my friend who is clearly falling-down drunk "How many beers did you have?" and he says "Ummm.. half a dozen?", I will be inclined to think that half a dozen is actually 8 or 9.

So, context is king; if you are in a situation where something is normally expressed as an exact number, then "half a dozen" equals 6. But if you are in a situation where the exact number doesn't necessarily matter or may not be known, then "half a dozen" is "most likely somewhere between 4 and 8".

Solution 2:

Curiously, the OED says:

half-dozen | half-a-dozen

The half of a dozen; six (or about six).

In its quotes, it does not distinguish when it means 6 and when it means ~6.

But for dozen, the OED does not depart from 12.

dozen

A group or set of twelve. Originally as a n., followed by of, but often with ellipsis of of, and thus, in singular = twelve. Also, used colloq. in pl., either indefinitely or hyperbolically, for any moderately large number; cf. hundred n. and adj. 2. (Abbreviated doz.)

The OED gives no example of 'dozen' meaning 'about 12'.

Originally dozen was a noun, and so a dozen of eggs meant twelve eggs not somewhere between 10 and 14.

It does say that dozens can mean a moderately large number, just as hundreds can mean a large number.

This is not to get all prescriptive. People can use words in any manner they want. I'm just saying that a dozen equals twelve and a half dozen is six, or 'around six'.

Edit to add that a dozen dozen equals a gross, which is exactly 144, not around 144 or between, say, 122 and 166.

Solution 3:

It depends on the context.

If I'm buying eggs from a supermarket then I assume they're selling an exact quantity (i.e. 6).

In that context the reason for saying "a half dozen" is that eggs are traditionally sold by the dozen.

You quoted it being used in the following context:

Story goes, he made thirteen bullets. This hunter used the gun a half dozen times before he disappeared, the gun along with him...

In that context I assume it's imprecise.

If they had wanted to specify any precise number, they could have said, "This hunter used the gun six times...".

In that context the reason for saying "a half dozen" is that it's an (imprecise) estimate.