1705, from tape (n.) + worm (n.); so called for its ribbon-like shape.
Entries linking to tapeworm
tape n.
Old English tæppe "narrow strip of cloth used for tying, measuring, etc.," of uncertain origin; perhaps [Klein] a back-formation from Latin tapete "cloth, carpet," compare also Old Frisian tapia, Middle Low German tapen "to pull, pluck, tear." The original short vowel became long in Middle English.
Adhesive tape is from 1885; also in early use sometimes friction tape. Tape recorder "device for recording sound on magnetic tape" first attested 1932; from earlier meaning "device for recording data on ticker tape" (1892), from tape in the sense of "paper strip of a printer" (1884). Tape-record (v.) is from 1950. Tape-measure is attested from 1873; tape-delay is from 1968.
worm n.
Old English wurm, variant of wyrm "serpent, snake, dragon, reptile," also in later Old English "earthworm," from Proto-Germanic *wurmiz (source also of Old Saxon, Old High German, German wurm, Old Frisian and Dutch worm, Old Norse ormr, Gothic waurms "serpent, worm"), from PIE *wrmi- "worm" (source also of Greek rhomos, Latin vermis "worm," Old Russian vermie "insects," Lithuanian varmas "insect, gnat"), from PIE *wrmi- "worm," from root *wer- (2) "to turn, bend."
The ancient category of these was much more extensive than the modern, scientific, one and included serpents, scorpions, maggots, and the supposed causes of certain diseases. For substitution of -o- for -u-, see come. As an insult meaning "abject, miserable person" it dates from Old English. Worms "any disease arising from the presence of parasitic worms" is from late Old English. Can of worms figurative for "difficult problem" is from 1951, from the literal can of worms a fisherman might bring with him, on the image of something all tangled up.