The Collaborative International Dictionary of English v.0.48:

Tipula \Tip"u*la\, n.; pl. L. Tipulae, E. Tipulas. [L., the
   water spider, or water spinner.] (Zool.)
   Any one of many species of long-legged dipterous insects
   belonging to Tipula and allied genera. They have long and
   slender bodies. See Crane fly, under Crane.
   [1913 Webster]