worm

As nouns the difference between worm and alvinellid

is that worm is while alvinellid is any of several polychaete worms, of the family (taxlink) , endemic to hydrothermal vents in the pacific ocean.

As nouns the difference between worm and hemichordate

is that worm is a generally tubular invertebrate of the annelid phylum while hemichordate is any of many marine worms, of the phylum Hemichordata, that have a primitive notochord.

As a verb worm

is to make (one's way) with a crawling motion.

As an adjective hemichordate is

of, pertaining to, or characteristic of these animals.