British variant spelling of cosseting; present participle of cosset in British English.
From cosset + -ting (British present participle, doubling the final consonant). British convention doubles consonants before -ing after a short vowel.
Even this everyday word shows the British-American split: Americans write 'cosseting' while Brits write 'cossetting'—it's a tiny mark of identity that divides English speakers on both sides of the Atlantic.
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