rack1
noun
- 1a framework, typically with rails, bars, hooks, or pegs, for holding or storing things: a spice rack a letter rack
- an overhead shelf on a coach, train, or aircraft for stowing luggage.
- a stack of digital effects units for a guitar or other instrument.
- a vertically barred frame for holding animal fodder: a hay rack
- 2a cogged or toothed bar or rail engaging with a wheel or pinion, or using pegs to adjust the position of something: a steering rack
verb
- 1 (also wrack) cause extreme pain, anguish, or distress to: he was racked with guilt
- historical torture (someone) on the rack.

Phrases
-
go to rack (or wrack) and ruin
- gradually deteriorate in condition because of neglect; fall into disrepair.[rack from Old English wræc 'vengeance'; related to wreak]
-
off the rack
- North American term for off the peg (see peg).
-
on the rack
- suffering intense distress or strain.
-
rack (or wrack) one's brains (or brain)
- make a great effort to think of or remember something: Meg racked her brain for inspiration

Origin:
Middle English: from Middle Dutch rec, Middle Low German rek 'horizontal bar or shelf', probably from recken 'to stretch, reach' (possibly the source of rack1 (sense 1 of the verb))

The relationship between the forms rack and wrack is complicated. The most common noun sense of rack, ‘a framework for holding and storing things’, is always spelled rack, never wrack. In the phrase rack something up the word is also always spelled rack. Figurative senses of the verb, deriving from the type of torture in which someone is stretched on a rack, can, however, be spelled either rack or wrack: thus racked with guilt or wracked with guilt; rack your brains or wrack your brains. In addition, the phrase rack and ruin can also be spelled wrack and ruin.