Definition of rack noun from the Oxford Advanced Learner's Dictionary

rack

noun

ræk

ræk

1 (often in compounds) a piece of equipment, usually made of metal or wooden bars, that is used for holding things or for hanging things ona vegetable/wine/plate/toast rackI looked through a rack of clothes at the back of the shop.Remove the cakes from the oven and cool on a wire rack. see also luggage rack, roof rack2 (usually the rack) an instrument of torture, used in the past for punishing and hurting people. Their arms and legs were tied to the wooden frame and then pulled in opposite directions, stretching the body.3 rack of lamb/pork a particular piece of meat that includes the front ribs and is cooked in the oven4 a part of a machine that consists of a bar with parts that a wheel or gear can fit into

Idioms

go to rack and ruin

to get into a bad condition

They let the house go to rack and ruin.

off the rack

(North American English) (British English off the peg) (of clothes) made to a standard average size and not made especially to fit you

on the rack

feeling extreme pressure, anxiety or pain