worm: 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
entity: that which is perceived or known or inferred to have its own distinct existence (living or nonliving)
alloy iron: cast iron containing alloying elements (usually nickel or chromium or copper or molybdenum) to increase the strength or facilitate heat treatment