Plural of drammock; multiple servings or batches of oatmeal-based food mixed with fat or whisky.
From drammock + -s (plural marker). Standard English pluralization adding -s to nouns.
The plural form shows this food was common enough and eaten regularly enough that people needed to talk about making multiple batches, which tells us it wasn't a fancy dish but everyday sustenance for working people in the Scottish Highlands.
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