The Collaborative International Dictionary of English v.0.48:

Tiller \Till"er\, n. [From Till, v. t.]
   One who tills; a husbandman; a cultivator; a plowman.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tiller \Till"er\, n. [AS. telgor a small branch. Cf. Till to
   cultivate.]
   1. (Bot.)
      (a) A shoot of a plant, springing from the root or bottom
          of the original stalk; a sucker.
      (b) A sprout or young tree that springs from a root or
          stump.
          [1913 Webster]

   2. A young timber tree. [Prov. Eng.] --Evelyn.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tiller \Till"er\, n. [From OE. tillen, tullen, to draw, pull;
   probably fr. AS. tyllan in fortyllan to lead astray; or cf.
   D. tillen to lift up. Cf. Till a drawer.]
   1. (Naut.) A lever of wood or metal fitted to the rudder head
      and used for turning side to side in steering. In small
      boats hand power is used; in large vessels, the tiller is
      moved by means of mechanical appliances. See Illust. of
      Rudder. Cf. 2d Helm, 1.
      [1913 Webster]

   2. The stalk, or handle, of a crossbow; also, sometimes, the
      bow itself. [Obs.]
      [1913 Webster]

            You can shoot in a tiller.            --Beau. & Fl.
      [1913 Webster]

   3. The handle of anything. [Prov. Eng.]
      [1913 Webster]

   4. A small drawer; a till. --Dryden.
      [1913 Webster]

   Tiller rope (Naut.), a rope for turning a tiller. In a
      large vessel it forms the connection between the fore end
      of the tiller and the steering wheel.
      [1913 Webster] Tilley

WordNet (r) 3.0 (2006):

tiller
    n 1: a shoot that sprouts from the base of a grass
    2: someone who tills land (prepares the soil for the planting of
       crops)
    3: lever used to turn the rudder on a boat
    4: a farm implement used to break up the surface of the soil
       (for aeration and weed control and conservation of moisture)
       [syn: cultivator, tiller]
    v 1: grow shoots in the form of stools or tillers [syn: stool,
         tiller]