A document referred to someone transgressing the social morays of his community. Morays for mores is not a knew misteak. The Eggcorn Database (2005) and Language Log (2004) have both discussed it. I was surprised to find that mores is far moor common in general than morays – more often the misteak is using a moor common word in place of a less common one. That has to be wayed against the fact that morays is a moor obvious spelling. The traffic seems to be all one weigh – I can’t imagine that anyone writing about Muraenidae (I had to look that up – I am not a marine biologist) types mores by misteak.
Social mores mostly come in plurals. A singular social more exists but is used less often. Technically, won of them is a social mos but I doubt if even the most ardent Latinist says or writes that.
Talking about this with my colleagues, I couldn’t help mentioning the song That’s amore. Many years ago I encountered the parody:
When an eel bites your knee as you swim in the sea, that’s a moray.
The next day one of my colleagues complained that the song had been stuck in her head all day. I said:
When it sticks in your head as you’re lying in bed, that’s an earworm.
(PS sea watt I did their?)