The Collaborative International Dictionary of English v.0.48:

Sprout \Sprout\ (sprout), v. i. [imp. & p. p. Sprouted; p. pr.
   & vb. n. Sprouting.] [OE. sprouten, spruten; akin to
   OFries. spr[=u]ta, AS. spre['o]tan, D. spruiten, G.
   spriessen, Sw. spruta to squirt, to spout. Cf. Sprit, v. t.
   & i., Sprit a spar, Spout, v. t., Spurt.]
   1. To shoot, as the seed of a plant; to germinate; to push
      out new shoots; hence, to grow like shoots of plants.
      [1913 Webster]

   2. To shoot into ramifications. [Obs.] --Bacon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sprouting
    n 1: the process whereby seeds or spores sprout and begin to
         grow [syn: germination, sprouting]