worm

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various invertebrates, especially an annelid, flatworm, nematode, or nemertean, having a long, flexible, rounded or flattened body, often without obvious appendages.
• noun Any of various crawling insect larvae, such as a grub or a caterpillar, having a soft elongated body.
• noun Any of various other animals, such as a shipworm or a slowworm, having a long slender limbless body.
• noun Something, such as the thread of a screw or the spiral condenser in a still, that resembles a worm in form or appearance.
• noun The spirally threaded shaft of a worm gear.
• noun An insidiously tormenting or devouring force.
• noun A person regarded as pitiable or contemptible.
• noun Medicine Infestation of the intestines or other parts of the body with parasitic worms; helminthiasis.
• noun Computers A malicious program that replicates itself until it fills all of the storage space on a drive or network.
• intransitive verb To make (one's way) with the sinuous crawling motion of a worm.
• intransitive verb To work (one's way or oneself) subtly or gradually; insinuate.
• intransitive verb To elicit by artful or devious means. Usually used with out of.
• intransitive verb To cure of intestinal worms.
• intransitive verb Nautical To wrap yarn or twine spirally around (rope).
• intransitive verb To move in a manner suggestive of a worm.
• intransitive verb To make one's way by artful or devious means.

from The Century Dictionary.

• noun A conical winding-drum having a spiral groove in which the winding rope or chain lies as it is wound upon the drum, the object being to wind the rope at first over the smaller diameter of the cone, and to increase the leverage as the winding proceeds. A common example is the brake-chain worm of a railroad car at the lower end of a brake-shaft.
• noun The driving element in screw-gearing or worm-gearing; the helix whose section is that of a wheel-tooth described upon a cylinder as a base which bears upon the tooth of the worm-wheel to cause the latter to revolve.
• To move like a worm; go or advance as a worm; crawl or creep sinuously; wriggle; writhe; squirm: as, to worm along.
• To work or act slowly, stealthily, or secretly.
• To effect by slow, stealthy, or insidious means: as, to worm one's way along.
• Specifically
• To extract, remove, expel, or take away by underhand means persistently continued: generally with out or from.
• To subject to a stealthy process of ferreting out one's secrets or private affairs; play the spy upon.
• To free from worms.
• To remove the charge, etc., from, as a gun, by means of a worm. See worm, n., 6 .
• To remove the worm or lytta from the tongue of, as of a dog: supposed to be a precaution against madness.
• To remove the beard of (an oyster or mussel).
• To give a spiral form to; put a thread on.
• Nautical, to wind rope-yarns, spun yarn, or similar material spirally round (a rope) so as to fill the spaces between the strands and render the surface smooth for parceling and serving. See cuts under parceling and serving-mallet.
• noun In popular language, any small creeping creature whose body consists of a number of movable joints or rings, and whose limbs are very short or entirely wanting; any vermiform animal.
• noun Any annelid, as the earthworm, lobworm or lugworm, leech, etc. See the distinctive names.
• noun Any helminth, whether parasitic or not, as a flat-worm, brain-worm, fluke-worm, roundworm, tapeworm, pinworm, hairworm, threadworm, spoonworm, longworm, whirl-worm, guinea-worm, etc. See such words, and vinegar-eel.
• noun One of several long slender vermiform echinoderms, as some holothurians and related forms. See Vermiformia, and cuts under Synapta and trepang.
• noun Some small or slender acarine or mite, or its larva, as the worm found in sebaceous follicles. See comedo and Demodex.
• noun A myriapod; a contiped or milleped; a gally-worm.
• noun The larva, grub, maggot, or caterpillar of many true hexapod insects: as, bag-worm; boll-worm; book-worm; wire-worm; sod-worm; snake-worm; joint-worm; silkworms. See the compounded and otherwise qualified names.
• noun The adult of some true insects whose body is long and flexible, as a glow-worm.
• noun One of several long slender crustaceans with short legs or none, which attach to or burrow in other animals, bore into wood, etc., as some kinds of fish-lice, certain isopods (as the gribble), certain amphipods (as the wood-shrimp), etc.
• noun One of some vermiform mollusks, as a teredo or shipworm, or a wormshell. See cuts under shipworm and Vermetus.
• noun A small lizard with rudimentary legs, or none, as a blindworm or slow-worm.
• noun A serpent; a snake; a dragon. For a modern instance in composition, see worm-snake, 1.
• noun Technically, in zoology, any member of the Linnean class Vermes, or of the modern phylum or subkingdom of the same name; any turbellarian, planarian, nemertean, platyhelminth, nemathelminth, trematoid, cestoid, nematoid, chætognath, gephyrean, annelid, etc.
• noun A person or human being likened to a worm as an object of scorn, disgust, contempt, pity, and the like: as, man is but a worm of the dust.
• noun Figuratively, of inanimate objects, something that slowly, silently, or stealthily eats, makes, or works its way, to the pain, injury, or destruction of the object affected: used emblematically or symbolically.
• noun An uneasy conscience; the gnawing or torment of conscience; remorse.
• noun In anatomy, some vermiform part or process of an animal's body.
• noun Anything thought to resemble a worm in appearance, or in having a spiral or curved movement.