'cold shoulder' originates from English usage of the noun phrase describing the literal 'cold shoulder' of meat served to an unwelcome guest; the phrase was used metaphorically in English in the early 19th century.

'cold shoulder' changed from a literal practice (serving a 'cold shoulder' of meat) and by the early 1800s began to be used figuratively to mean treating someone with deliberate coldness, eventually becoming the idiomatic expression 'cold shoulder' or the verb 'cold-shoulder'.

Initially, it meant 'a shoulder of meat served cold' (literal); over time it evolved into its current meaning of 'deliberate unfriendly treatment or snubbing' (figurative).