Source : Webster's Revised Unabridged Dictionary (1913)

Icicle \I"ci*cle\, n. [OE. isikel, AS. [=i]sgicel; [=i]s ice +
   gicel icicle; akin to Icel. j["o]kull; cf. Gael. eigh ice,
   Ir. aigh.]
   A pendent, and usually conical, mass of ice, formed by
   freezing of dripping water; as, the icicles on the eaves of a
   house.

Source : WordNet®

icicle
     n : a pendent spear of ice formed by the freezing of dripping
         water