Literal translation
as big as a stockfish
Meaning
extremely thin
Explanation
Said of someone very thin, by ironic antiphrasis, estocafisso being the thin, stiff dried cod that came from Scandinavian countries. The phrase traditionally closes a letter or postcard sent to close family or friends, playing on the idea that there's room enough for everyone. It extends a Provençal usage where faire caresso means making a friendly gesture, hence grosso caresso to express great affection at the end of an exchange.