lug-worm n.

type of large worm inhabiting muddy and sandy soil along seashores, also lugworm, 1802, with worm (n.) + lug, which by itself was the older name for the worm (c. 1600). This is perhaps from lug, noun or verb (on the notion of "heavy, clumsy"), or perhaps it is from a Celtic word (the first recorded use is in a Cornwall context).