A creeping or a crawling animal of any kind or size, as a serpent, caterpillar, snail, or the like.
- Any of various invertebrates, as those of the phyla Annelida, Nematoda, Nemertea, or Platyhelminthes, having a long, flexible, rounded or flattened body, often without obvious appendages.
- Any of various crawling insect larvae, such as a grub or a caterpillar, having a soft elongated body.
- Any of various unrelated animals, such as the shipworm or the slowworm, resembling a worm in habit or appearance.
- Something, such as the thread of a screw or the spiral condenser in a still, that resembles a worm in form or appearance.
- The spirally threaded shaft of a worm gear.
- An insidiously tormenting or devouring force: "felt the black worm of treachery growing in his heart” ( Mario Puzo).
- A person regarded as pitiable or contemptible.
- Pathology Infestation of the intestines or other parts of the body with worms or wormlike parasites; helminthiasis.
- Computer Science A malicious program that replicates itself until it fills all of the storage space on a drive or network.
- To make (one's way) with or as if with the sinuous crawling motion of a worm.
- To work (one's way or oneself) subtly or gradually; insinuate: She wormed her way into his confidence.
- To elicit by artful or devious means. Usually used with out of: wormed a confession out of the suspect.
- To cure of intestinal worms.
- Nautical To wrap yarn or twine spirally around (rope).
- To move in a manner suggestive of a worm.
- To make one's way by artful or devious means: He can't worm out of this situation.