Source : Webster's Revised Unabridged Dictionary (1913)

Tiller \Till"er\, v. i. [imp. & p. p. {Tillered}; p. pr. & vb.
   n. {Tillering}.]
   To put forth new shoots from the root, or round the bottom of
   the original stalk; as, wheat or rye tillers; some spread
   plants by tillering. [Sometimes written {tillow}.]