any of various worms living parasitically in intestines of vertebrates having a retractile proboscis covered with many hooked spines | any of numerous relatively small elongated soft-bodied animals especially of the phyla Annelida and Chaetognatha and Nematoda and Nemertea and Platyhelminthes; also many insect larvae |
| screw thread on a gear with the teeth of a worm wheel or rack |
| a software program capable of reproducing itself that can spread from one computer to the next over a network |
| a person who has a nasty or unethical character undeserving of respect |