cold shoulder

noun

A deliberate slight: cut, rebuff, snub, spurn. Informal go-by. See accept/reject.

Deliberate coldness or disregard, a slight or snub. For example, When I said hello to her in the library, she gave me the cold shoulder and walked away. This term, which first appeared in writings by Sir Walter Scott and others, supposedly alludes to the custom of welcoming a desired guest with a meal of roasted meat, but serving only a cold shoulder of beef or lamb--a far inferior dish--to those who outstayed their welcome. [Early 1800s]