screwworm

the term 'screwworm' is a vivid compound noun formed in american english during the late 19th century to describe a particularly destructive parasitic larva. the first element, 'screw', does not refer to the fastener but metaphorically captures the distinctive corkscrew motion with which the larva burrows into living tissue, reminiscent of a screw penetrating wood. the second element, 'worm', is a generic old english term for a creeping animal, here specifying the creature's larval form. this compound efficiently visualizes the pest's most damaging behavioral trait, creating a name that is both descriptive and foreboding for livestock owners.

Structure: screw + worm screw (from middle english 'screwe', of uncertain origin, perhaps from old french 'escroue', denoting a cylindrical object; in this compound, it describes the spiral or corkscrew-like burrowing pattern). worm (from old english 'wyrm', meaning a creeping or crawling animal, especially a helminth or larva).