British slang: to stick, clog, or paste something together; to adhere or become stuck.
From Middle English 'claggen' (to stick), possibly related to Old Norse words. Used in British English since at least the 16th century for adhesion or sticking.
In Britain, 'clag' is playground slang—kids use it to describe sticky substances like glue or even the feeling of humid air making clothes stick to skin.
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