The below meanings are from an online dictionary. Coddle and cosset seem to have a similar meaning in that they suggest someone is being treated in an overprotective way. To pamper someone is to treat them well and spoil them, it is not so much about being overprotective. Hope this helps. Coddle - treat (someone) in an indulgent or overprotective way. "I was coddled and cosseted" Pamper - indulge with every attention, comfort, and kindness; spoil. Cosset - care for and protect in an overindulgent way. "all her life she'd been cosseted by her family."

They're all synonyms. Cosset is formal.

Coddle and pamper are pretty similar, but used in different situations. To coddle someone or something usually means to treat very carefully or very gently. example: She coddled the sick child. To pamper usually means treating more excessively or more indulgently. example: It was her 50th birthday, so she went to the spa to pamper herself. I am a native speaker from the U.S., and I don't know the word cosset - it is not used commonly here.