Superlative form of 'cotty,' meaning most resembling or characteristic of a cottage, or most cottage-like in appearance or feel.
From cot/cottage + -y (adjective suffix) + -est (superlative). This is an informal colloquial formation rather than a standard dictionary word.
While 'cottiest' isn't in most dictionaries, English speakers instantly understand it—the superlative -est suffix is so powerful that we can apply it to almost any adjective, creating words on the fly!
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