Old English webb "woven fabric, woven work, tapestry," from Proto-Germanic *wabjam "fabric, web" (source also of Old Saxon webbi, Old Norse vefr, Dutch webbe, Old High German weppi, German gewebe "web"), from PIE *webh- "to weave" (see weave (v.)).
Meaning "spider's web" is first recorded early 13c. Applied to the membranes between the toes of ducks and other aquatic birds from 1570s. Internet sense is from 1992, shortened from World Wide Web (1990). Web browser, web page both also attested 1990.