Drupal is an English rendering of the Dutch word “druppel”, which means “drop” (as in “a water droplet”). The choice of “drop” was merely coincidental, Dries Buytaert the original writer wanted to register dorp.org (meaning “village” in Dutch, in reference to his program’s community aspect) Dries made a typo when checking the domain name and thought it sounded better.
Source: http://hehe2.net/apps/etymology-of-an-open-source-appproject/