Present participle of an archaic or rare verb 'cose,' meaning to chat or converse familiarly; making cosy or nestling.
From Middle English 'cosen' (to chat), possibly from Old Norse origins. This is an extremely archaic term barely used in modern English.
This word is so old and rare that most dictionaries barely mention it—finding it in a text usually means the author is being deliberately archaic or whimsical.
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