“s**t” with the indefinite article?

Question

...and there’s a bill for £300, and an actual human shit in the ashtray. Well, I think it’s a shit. I’m standing up and freaking out – totally freaking out – and shouting “This is a shit! This is an actual human shit!”

It's a short excerpt from a book by a British writer. As far as I know, ‘shit’ in the sense of solid body waste is an uncountable word. Of course there are idiomatic expressions like take a shit/have a shit, but it's not the case here. So can anybody explain why the author uses a/an with ‘shit’?

Answer 1

This is somewhat similar to the question about using an indefinite article with "water". In English, we often use the indefinite article with an uncountable noun as a short cut to mean "one portion/serving of [noun]."

That's what the usage "take a shit" does - it uses the indefinite article to say that the person doing the action is going to create one "portion" of shit from beginning to end, just like "I'd like a coffee" says that you want one cup of coffee, even though the noun coffee is normally uncountable.

In your example, the speaker is using "a shit" to emphasize that it is one entire piece of shit of the size that a person would usually produce in one, um, sitting. This makes the literary effect more vivid than just saying "some shit," which could be a little smear or a small amount. Instead, this definite article is telling you that someone apparently performed a full and entire excretory activity directly into the ashtray.

I do believe that this particular usage of "a shit" is more common in British English than in American English - your excerpt reminds me of an Irvine Welsh novel. In American English, as mentioned in the comments, it would be more usual to refer to the object as "a turd" or something like that.

Answer 2

shit is uncountable when it refers to the excrement itself.

When it refers to the bodily process, it can be countable.

Answer 3

From Wiktionary:

Noun

shit (usually uncountable, plural shits)

1. (countable, uncountable, colloquial, vulgar) Solid excretory product evacuated from the bowels; feces.

Note:

• usually uncountable, plural shits
• (countable, uncountable, colloquial, vulgar)

Even though it's usually uncountable it still has a plural, and the literal faeces can be both countable and uncountable. You are correct that shit is uncountable, but contrary to what you'd expect, this does not mean it can't also be countable at the same time.

So, This is a shit! This is an actual human shit! needs no further explanation.