1.  caterpillar(n = noun.animal) - a wormlike and often brightly colored and hairy or spiny larva of a butterfly or moth;
is a kind of larva
is a member of lepidoptera, order lepidoptera
has particulars: tussock caterpillar, cankerworm, inchworm, looper, measuring worm, phthorimaea operculella, potato tuberworm, cutworm, army worm, armyworm, pseudaletia unipuncta, beet armyworm, spodoptera exigua, fall armyworm, spodoptera frugiperda, manduca sexta, tobacco hornworm, tomato worm, manduca quinquemaculata, potato worm, tomato hornworm, silkworm, giant silkworm, silkworm, wild wilkworm, tent caterpillar, lappet caterpillar, webworm, corn borer, pyrausta nubilalis, bollworm, cabbageworm, pieris rapae, woolly bear, woolly bear caterpillar

2.  caterpillar(n = noun.artifact) cat - a large tracked vehicle that is propelled by two endless metal belts; frequently used for moving earth in construction and farm work;
is a kind of tracked vehicle

1.  The larval state of a butterfly or any lepidopterous insect; sometimes, but less commonly, the larval state of other insects, as the sawflies, which are also called false caterpillars. The true caterpillars have three pairs of true legs, and several pairs of abdominal fleshy legs (prolegs) armed with hooks. Some are hairy, others naked. They usually feed on leaves, fruit, and succulent vegetables, being often very destructive, Many of them are popularly called worms, as the cutworm, cankerworm, army worm, cotton worm, silkworm. [1913 Webster]

2.  A plant of the genus Scorpiurus, with pods resembling caterpillars. [1913 Webster]

caterpillar, n.
1 a the larva of a butterfly or moth. b (in general use) any similar larva of various insects.
2 (Caterpillar) a (in full Caterpillar track or tread) propr. a steel band passing round the wheels of a tractor etc. for travel on rough ground. b a vehicle with these tracks, e.g. a tractor or tank.

Etymology:
perh. AF var. of OF chatepelose lit. hairy cat, infl. by obs. piller ravager

N  infant, babe, baby, babe in arms, nurseling, suckling, yearling, weanling, papoose, bambino, kid, vagitus, child, bairn, little one, brat, chit, pickaninny, urchin, bantling, bratling, elf, youth, boy, lad, stripling, youngster, youngun, younker, callant, whipster, whippersnapper, whiffet, schoolboy, hobbledehoy, hopeful, cadet, minor, master, scion, sap, seedling, tendril, olive branch, nestling, chicken, larva, chrysalis, tadpole, whelp, cub, pullet, fry, callow, codlin, codling, foetus, calf, colt, pup, foal, kitten, lamb, lambkin, aurelia, caterpillar, cocoon, nymph, nympha, orphan, pupa, staddle, girl, lass, lassie, wench, miss, damsel, demoiselle, maid, maiden, virgin, hoyden, infantine, infantile, puerile, boyish, girlish, childish, babyish, kittenish, baby, newborn, unfledged, new-fledged, callow, in the cradle, in swaddling clothes, in long clothes, in arms, in leading strings, at the breast, in one's teens.

N  vehicle, conveyance, carriage, caravan, van, common carrier, wagon, waggon, wain, dray, cart, lorry, truck, tram, cariole, carriole, limber, tumbrel, pontoon, barrow, wheel barrow, hand barrow, perambulator, Bath chair, wheel chair, sedan chair, chaise, palankeen, palanquin, litter, brancard, crate, hurdle, stretcher, ambulance, black Maria, conestoga wagon, conestoga wain, jinrikisha, ricksha, brett, dearborn, dump cart, hack, hackery, jigger, kittereen, mailstate, manomotor, rig, rockaway, prairie schooner, shay, sloven, team, tonga, wheel, hobbyhorse, go-cart, cycle, bicycle, bike, two-wheeler, tricycle, velocipede, quadricycle, equipage, turn-out, coach, chariot, phaeton, break, mail phaeton, wagonette, drag, curricle, tilbury, whisky, landau, barouche, victoria, brougham, clarence, calash, caleche, britzka, araba, kibitka, berlin, sulky, desobligeant, sociable, vis-a-vis, dormeuse, jaunting car, outside car, dandi, doolie, dooly, munchil, palki, roller skates, skate, runabout, ski, tonjon, vettura, post chaise, diligence, stage, stage coach, mail coach, hackney coach, glass coach, stage wagon, car, omnibus, fly, cabriolet, cab, hansom, shofle, four-wheeler, growler, droshki, drosky, dogcart, trap, whitechapel, buggy, four-in-hand, unicorn, random, tandem, shandredhan, char-a-bancs, motor car, automobile, limousine, car, auto, jalopy, clunker, lemon, flivver, coupe, sedan, two-door sedan, four-door sedan, luxury sedan, wheels, sports car, roadster, gran turismo, jeep, four-wheel drive vehicle, electric car, steamer, golf cart, electric wagon, taxicab, cab, taxicoach, checker cab, yellow cab, station wagon, family car, motorcycle, motor bike, side car, van, minivan, bus, minibus, microbus, truck, wagon, pick-up wagon, pick-up, tractor- trailer, road train, articulated vehicle, racing car, racer, hot rod, stock car, souped-up car, bob, bobsled, bobsleigh, cutter, double ripper, double runner, jumper, sled, sledge, sleigh, toboggan, train, accommodation train, passenger train, express trail, special train, corridor train, parliamentary train, luggage train, freight train, goods train, 1st class train, 2nd class train, 3rd class train, 1st class carriage, 2nd class carriage, 3rd class carriage, 1st class compartment, 2nd class compartment, 3rd class compartment, rolling stock, horse box, cattle truck, baggage car, express car, freight car, parlor car, dining car, Pullman car, sleeping car, sleeper, dome car, surface car, tram car, trolley car, box car, box wagon, horse car, bullet train, shinkansen, cannonball, the Wabash cannonball, lightning express, luggage van, mail, mail car, mail van, shovel, spool, spatula, ladle, hod, hoe, spade, spaddle, loy, spud, pitchfork, post hole digger, tractor, steamshovel, backhoe, fork lift, earth mover, dump truck, bulldozer, grader, caterpillar, trench digger, steamroller, pile driver, crane, wrecking crane.

caterpillar track, caterpillar tread, forest tent caterpillar, lappet caterpillar, tent caterpillar, tussock caterpillar, woolly bear caterpillar