Dictionary Definition:
Cakka (nt.) [Vedic cakra, redupl. formation fr. *quel to turn round (cp. P. kaṇṭha > Lat. collus & see also note on gala)=that which is (continuously) turning, i. e. wheel, or abstr, the shape or periphery of it, i. e. circle. Cakra=Gr. ku/klos, Ags. hveohl, hveol=wheel. The unredupl. form in Sk. carati (versatur), Gr. pe/lomai, poleu/w, po/los (pole); Lat. colo, incolo; Obulg. kolo wheel, Oisl. hvel] I. Crude meaning: 1. a wheel (of a carriage) Dh 1; PvA 65 (ratha˚); Miln 27. -- 2. a discus used as a missile weapon J i.74; Pgdp 36; cp. khura˚ a razor as an instr. of torture. -- 3. a disc, a circle: heṭṭhāpādatalesu cakkāni jātāni, forming the 2ndcharacteristic mark of a Mahāpurisa D ii.17= iii.143; D iii.149. -- J ii.331; Miln 51. -- 4. an array of troops (under tayo vyūhā: paduma˚ cakka˚ sakaṭa˚) Jii.404=iv.343. -- II. Applied meaning: 1. (a wheel as component part of a carriage, or one of a duad or tetrad=) collection, set, part; succession; sphere, region, cycle Vin i.330 (cp. Vin. Texts ii.281); iii.96; iriyāpatha˚ the 4 ways of behaviour, the various positions (standing, walking, sitting, lying down) DA i.249;Sdhp 604. sā˚, miga˚ the sphere or region of dogs & wild animals Miln 178; cakkena (instr.) in succession PvA iii. cakkaŋ kātabbaŋ, or bandhitabbaŋ freq. in Yam. and Paṭṭh, "The cycle of formulated words is to be here repeated." -- 2. (like the four wheels constituting the moving power of a carriage=) a vehicle, instrument, means & ways; attribute, quality; state, condition, esp. good condition (fit instrumentality), catucakka an instr. of four, a lucky tetrad, a fourwheeler of the body as expressing itself in the four kinds of deportment, iriyāpathas A ii.32; S i.16, 63 (catucakkaŋ). In this sense generalized as a happy state, consisting of "4 blessings": paṭirūpadesa -- vāsa, sappurisûpassaya, atta -- sammāpaṇidhi, pubbe -- kata -- puññatā A ii.32; J v.114; mentioned at Ps i.84. Cp. also Sn 554 sq.; 684. Esp. pronounced in the two phrases dhamma -- cakka (the wheel of the Doctrine, i. e. the symbol of conquering efficacy, or happiness implicated in the D.) and brahma -- c˚ the best wheel, the supreme instrument, the noblest quality. Both with pavatteti to start & kcep up (like starting & guiding a carriage), to set rolling, to originate, to make universally known. dhamma˚ e. g. S i.191; A i.23, 101; ii.34, 120; iii.151; iv.313; Sn 556 sq.; 693; J iii.412; Ps ii.159 sq.; PvA 67 (see dhamma). brahma˚ M i.71; S ii.27; A ii.9, 24; iii.9, 417; v.33; Vbh 317 sq.; 344 (see brahma). Cp. cakkavattin (below). -- Cp. vi˚.
-- chinna (udaka) (water of a well) the wheel of which is broken Ud 83; -- bhañjanin one who destroys a state of welfare & good J v.112 (patirāpadesavāsādino kusala -- cakkassa bhañjanī C.); -- bheda breaking peace or concord, sowing discord Vin ii.198; iii.171; -- yuga a pair of wheels Vv 832; -- ratana the treasure of the wheel, that is of the sun (cp. Rh. D. Buddh. Suttas p. 252; Dialogues ii.197, 102) D ii.171; iii.59 sq., 75; J i.63; ii.311; DA i.249. See also cakkavattin; -- vaṭṭaka (nt.) a scoop -- wheel (a wheel revolving over a well with a string of earthen pots going down empty & coming up full, after dredger fashion) Vin ii.122; -- vattin (cp. dhammacakkaŋ pavatteti above) he who sets rolling the Wheel, a just & faithful king (rājā hoti c. dhammiko dhammarājā cāturanto Sn p. 106, in corresp. pass. v. 1002 as vijeyya pathaviŋ imaŋ adaṇḍena asatthena dhammena -- m -- anusāsati). A definition is given by Bdhgh. at DA i.249. -- Three sorts of c. are later distinguished: a cakkavāla -- c˚ a universal king, or cāturanta -- c˚ (ruling over four great continents Sn p. 106; KhA 227), a dīpa -- c˚ (ruling over one), a padesa -- c˚ (ruling over part of one) Usually in phrase rājā cakka vattin: D i.88; iii.156; iv.302; v.44, 99, 342; D ii.16, 172; iii.59 sq., 75, 142 sq.; M iii.65; A i.76, 109 sq.;ii.37, 133, 245; iii.147 sq; 365; iv.89, 105; v.22; Kh viii.12 (˚sukha); J i.51; ii.395; iv.119; Vbh 336; PvA 117; VvA 18; Sdhp 238, 453; DhA ii.135 (˚sirī). -- ˚gabbha Vism 126: -- ˚rajjaŋ kāresi J ii.311; -- viddha (nt.) a particular form of shooting J v.130; -- samārūḷha (adj.) having mounted the wheels, i. e. their carts (of janapadā) A i.178; iii.66, 104.