You may want to see AWE's page distinguishing between the spellings rack and wrack
OED lists nineteen racks. Of these:
- no fewer than twelve nouns are written Rack, of which some ('a parrel-rope' (OED's n.1), 'the skin of a young rabbit' (n.12}, 'a fish-trap' (n.4, meaning 6. e), 'a measure [240 meshes] of pieces of lace' (4 meaning 7)) are marked 'obsolete'. The etymology of many is obscure and possibly interconnected. One at least (n.8) seems to be a copying error for 'rick', or its earlier form 'reacke'; and (n.9), (which appears in such phrases as 'to go to rack and ruin' (~ to come to a state of dilapidation or neglect'), is a variant of wrack, which is now the preferred spelling. N.11) is also a variant of wrack. N.10) is a variant of the name of the alcoholic drink arrack
The essential element in most of the racks likely to be of use to modern students seems to be 'a bar, or assembly of bars, for storage, display or confinement'.
- The earliest record (1343) is of "a vertically barred frame for holding animal fodder, either fixed to a wall or capable of being moved where required in a field or farmyard" (OED 2008, rack, n.4).
- This may be the root of a larger sense of rack (n.4, meaning 2) as a framework for storage, as may be seen in such current devices as clothes racks in shops, bicycle racks outside them, drying racks in houses, toast racks on tables and roof racks on cars. In table 'cue and ball' games like billiards, snooker and pool, the rack is the framework in which the balls are set out for the beginning of a game.
- N.3, meaning 2.b, is the name of "An instrument of torture, usually consisting of a frame on which the victim was stretched by turning two rollers fastened at each end to the wrists and ankles." It was much used in the later Tudor period to extract information, often on religious conspiracies. The phrase 'Come rack, come rope' (~ 'Let the worst [torture or execution] happen') is sometimes used: it is the title of an historical novel by R.H.Benson (1912). (The first meaning of rack n.3 was as the name of a frame on which cloth could be stretched (cf. v.1 below).)
- N.4, meaning 5 ('ratchet'), denotes a "A winding mechanism including a toothed wheel and a notched bar acting as a ratchet, used to draw some types of crossbow. Now hist. and rare." b "In extended use: a notched, cogged, or toothed bar for engaging a cogwheel, pinion, or worm so as to convert rotary into linear motion, or vice versa, or to adjust and hold the position of something." This is commonly seen in the rack and pinion mechanism, where a tooothed wheel (the pinion) engages with a straight toothed bar (the rack), as may be seen in stairlifts. It is used in the rack and pinion railway (rack railway in American English) used to help railway locomotives cope with steep slopes. One of the first steam locomotives used such a system (the Middleton Railway built to carry coal in the Leeds area).
- Less currently common meanings of rack include (n.2) a. 'a rush'; b. 'a scudding (quickly moving mass of high cloud)'; (OED 2008, rack, n.5) the 'reach' of a river or watercourse: a part which lies between two bends. OED notes magisterially that the resemblance between rack (or the historical raik) and reach "is perhaps only accidental"; (n.6) a horse's gait 'between a trot and a gallop' in which "both hooves on one side, the hind just before the front, are lifted before both those on the other side are set down, the hind also preceding the front, each contact with the ground being made at equal intervals" (OED); (n.7) a joint of meat containing several ribs, and formerly some of the neck. Nowadays used almost exclusively of lamb. A rack-bone used to be a vertebra; and an emaciated horse was said to be 'a rack of bones', or skeleton. The idea of 'a framework' presents itself.
- The seven verbs 'to rack' listed in OED, include
- (v.4) 'to provide with racks as frameworks for storage, etc.', in various senses
- The base meaning of (v.1) is "To stretch, pull out, increase the length of. Now rare". This developed from the use of n.2 by weavers to improve or standardize the finished lengths of cloth, which led to the meaning of 'to torture' by the use of n.3 (2b) above. Two figurative uses are
- rack-rent, extortionate rents charged to tenants, notoriously in the case of Ireland where, in imperial times, the mostly Roman Catholic peasantry were exploited by their wealthy Protestant landlords
- The phrase 'to rack [one's brains, memory or mind, etc.]' means to try hard ('to torture'} the relevant faculty in order to extract information or ideas from it
- v.5, described as 'now chiefly Scots', is used of the weather, meaning 'to clear up', 'to stop raining', etc. It originally meant, of clouds, 'to scud', 'to be blown away'.
- Technical terms:
- in brewing, etc., v.2 is 'to draw off liquid from the sediment that settles from it' - particularly alcoholic beverages, such as wine, beer, cider and mead, from the lees.
- in the subject of horses and riding, v.3 is 'to move, or to make a horse move, at a rack', n.6 above.
- in brick-laying and building, v.7 is "To build (a brick wall forming part of a corner) so that each course of bricks stops a little short of the one below, leaving the unfinished end of the wall stepped (until the work is later completed); to lay (bricks) in this manner. Usually with back".
- on board ships, v.6 is "To bind (two ropes) together by weaving an additional strand of material between and around them".